Just started in one myself for one of the mobile network providers.
Basic is £15,700 per annum but uncapped bonuses with very achievable targets.
Most in my department come out with about 2-4k per month before tax. But the biggest achiever in the centre came out with £76k in one year a few years back apparantly.
many other benefits as well such as,
-free fibre optic broadband
-40% off mobile contract for 5 friends and family including yourself per year
-huge discounts off many brands and delerships (15% off brand new BMW's Audis etc)
-subsidised canteen and costa (although they have vending machines all over with great tea and coffee inside absolutely free)
-first day I started for example the team im going into was taken to the beach for 3 hours in the afternoon and the company paid for fish and chips and ice cream for everyone.
-free concierge service (say you want to post a letter or buy a christmas present while at work or pick up a prescription, shell go out and do this for you)
-Free platinum health insurance
-free life assurance
-free dental
-good pension scheme
-many incentives to win 50 inch 3d tvs etc which happened yesterday to a few employees.
and many many more.
I honestly thought it was too good to be true when i first started but after speaking one to one with the guys on the shop floor it seems to be completely true and everyone seems extremely happy to be there.
I guess it depends which company and what department but I went in fully expecting all the horror storys about call centres to be true and here it just does not seem the case. Good luck btw.