I had an extremely bad experience with EE and would advise everyone to AVOID THIS PROVIDER BY ANY MEANS.

Several things were problematic with their service:

1) The internet speed was nowhere near to what they claimed it will be. I was paying for 17Mb/sec. However the actual speed was close to unusable and when I tested it with http://www.speedtest.net/ it would normally show me a download speed around 2Mb/sec.

2) After a couple of months, EE randomly charged me £240 without being able to explain why the charge has been made. I could only complain about this to the customer service over the phone, as employees in their stores claimed that they can not do anything about it. After countless calls and spending days on the phone (quite literally) I somehow convinced them to return the money. However, I had to repeat my calls several times to remind them they should return the money and they needed 4 months to actually do it.

3) Their salesperson simply lied about the terms and conditions before I signed the contract. They said I will not pay for the landline for the remaining months in the event of cancelation. However, after I decided to actually cancel the contract they claimed that this was not part of our agreement, which in the end cost me unanticipated £80.