Handling a relentless stream of inquiries from customers can be a tough calling.
Employees must have an encyclopaedic knowledge of all du's services, from the latest iPhone deal to the maze-like phone menus of a BlackBerry, to details of the operator's new Dh999-a-month internet package.
Difficult customers can also make working there stressful. But employees seem to thrive on the challenge.
Khaled Al Kendi, 28, who grew up in Fujairah, acknowledges manning the phone lines can be hard at times.
"Knowing this is the hardest job in the world, I tried to challenge myself," he says. "There are angry customers, talkative customers, sensitive customers, the happy ones ..."
Mr Al Kendi, who started working at the centre before its official opening last November, had received extensive training prior to hitting the phone lines.
While dealing with tricky callers can be challenging, the job has taught him how to better communicate with his friends and family.
"It changed me," says Mr Al Kendi.
"The way I deal with stress has changed. I used to shout sometimes, or I used to just quit and go outside. But now it's different. It helps you in your work, in your life."
The National spent the day at du's Fujairah call centre to observe the challenges involved in handling 1,500 calls from customers per day.
Sabir Khamis, the manager of du's call centre in Fujairah, is one of the first to arrive. The centre is located in a nondescript office building on Fujairah's main highway, with views to the mountains and the awe-inspiring Sheikh Zayed Mosque currently under construction.
About 60 staff are employed at the centre, working two shifts: 8am to 5pm; and 11am to 8pm. Another 60 staff are training prior to boosting the operation to provide 24-hour coverage, seven days a week.
The day starts with a 7.45am briefing led by team leaders, which Mr Khamis sits in on. Items on the agenda today include a technical problem, in which du's BlackBerry customers faced delays when switching price plans. While the problem has been solved, the centre is still receiving an increased number of calls because of it.
A board displaying the top-performing agents is prominently displayed in the office. "When you see your colleague is doing better than you, you will do your best," says Mr Khamis.
Maitha Al Kaabi, who started working at the centre in July and has already been promoted to team leader, monitors a screen that shows the status of the agents' calls. She follows up with agents if they place a customer on hold for too long.
Ms Al Kaabi says a problem with the mobile service can prompt a deluge of calls. "Sometimes we have an outage - like with the BlackBerry."
Calls are monitored for criteria including professionalism, accuracy and whether security measures were followed. If a team member scores poorly, they could receive additional coaching or - for repeat offenders - a verbal warning.
Ebraheim Al Hashemi, a customer service representative, is part of the team handling emails, Twitter and Facebook inquiries from customers. Today, he is working through a list of email inquiries in both Arabic and English. "Sometimes we receive emails from angry customers, but we apologise and try to calm them down," he says.
Saleem Al Balooshi, the executive vice president of customer operations at du, is paying one of his quarterly visits to the Fujairah call centre.
Du has other call centres in Dubai, Jordan, Egypt and India - but this one is unique in that it is staffed entirely by Emiratis.
Mr Al Balooshi says du received a total of 3,100 CVs for the 120 positions at the centre. Pay for the Emirati employees starts at Dh13,325 (US$3,627) a month, which includes a Dh4,000 premium on the equivalent wage for expatriates. It is part of an effort by du for 38 per cent of its staff to be UAE nationals by 2015.
On the floor above, two groups of new recruits are learning the complex customer-service system used by du. Many of them will end up working on the floor, which also includes separate men's and women's relaxation rooms.
Raed Haddad, a trainer employed by du, gives his students training on the system. But "soft" human skills - such as how to handle angry customers - are just as important.
"If we have a customer losing his mind, the first thing we do is listen," says Mr Haddad. "We let him let his anger out - we never interrupt."
Khaled Mohammed, 23, is one of the new recruits being trained. He grew up in Fujairah and is determined to pursue a career in the private sector.
"In Fujairah you do not have that many chances … So it's a great chance for me," he says. "If I can work at du, I can work in any private-sector company."
Mr Al Balooshi meets with the call-centre staff to hear their suggestions about improving customer service.
Calls to du's hotlines are filtered - with calls from Emirati, VIP and high-spending customers being directed to Fujairah.
Mr Al Balooshi says the majority of callers are happy but there are a few rare cases of nuisance calls.
"We had one person who called more than 300 times in one day," he says. This customer was added to a blacklist and was blocked from contacting the centre.
Another customer was blocked from calling the centre because he swore at staff. "We receive in a month a million calls and there are very few customers who have such behaviour," says Mr Al Balooshi.
Mr Khamis is meeting his team to discuss future plans and how to increase support for call-centre agents. Each employee has targets, detailing the number of calls and time spent handling enquiries. Reports are emailed to them each day.
About 20 staff are on the floor, as the early shift draws to a close. Mr Al Kendi says there is a daily handover of work to the late shift, involving complicated inquiries that could not be fixed earlier in the day. "We always follow up with each other, even sometimes after work."
Most people have now left the call centre - but the phones are still ringing.
Mozah Al Kendi, a customer care representative, is one of about six people still at the office, working the 11am to 8pm shift.
A customer calls requesting a change of their BlackBerry package from a national to international service. Speaking in Arabic into her headset, Ms Al Kendi first asks him security questions, then talks through the process. She does this from memory, all the while recording details using her keyboard. In this job, multi-tasking is a must.
Ms Al Kendi used to work in customer service for a big UAE retail firm but joined du last October. At first, she says, she found it difficult to deal with customers over the phone but is learning fast.
"Sometimes, I just listen."