Hi all, this is a bit long winded so please bear with it In dec 2011 i took a new contract with o2 running alongside an existing contract i had with them (been with o2 for the last 10 years), it was the usual thing with x amounts of minutes, texts and also data, however the first 2 bills i had i noticed i was being charged for data and being lazy i paid without checking i also added an upgrade to my account to allow for even more extra data, the third bill was i was also high so i decided to call them and find out why, o2 admitted to me on the phone that they had originally put me on the wrong contract due to an administration error and thats why i was charged for data, i asked for all charges to be refunded to which they agreed but then proceeded to debit to my account, another time consuming phone call and another admission of error they said these would be reflected in my next statement however again they failed to credit my account with the correct amount. I refused to pay and they started the threatening letters which i ignored, then they passed me on to a dca who asked for my financial details and got quite shirty when i refused that over the phone. Having not heard from O2 on this matter since and still having a different account with them i asumed the matter had been closed as a probable stalemate but have today checked my credit file and found they have added a default to the account and the cheeky so and so's have made it for the full amount after i changed the contract believing it to be my error. sorry for that, if you managed to get to the end and have any advice it would be appreciated. cheers.