6 months ago I purchased a mobile phone from carphone warehouse. I received the phone and returned the phone within the maximum alloted time; as it was not of the quality that I am accustomed to. 3-4 months later I received a debt collection letter saying that I owed vodafone 60 pound and was in breach of contract. I contacted the debt collection agency and said I had no contract with the firm and what on earth was this about. They confirmed that they believed I had not returned the phone and was in breach of contract. I contacted vodafone and they said that they had received the phone but that my contract has an outstanding balance of 30 pounds. I explained that I had not activated the phone and returned the phone and not accepted the contract. They had said that I had not cancelled in time even though the phone was returned in time and as I had cancelled my direct debit they reported me to a debt collection agency to retrieve the money. I asked them to cancel the contract before I reported them to the ombudsman. They said they would only do so if I paid a certain amount of money. I refused and told them that I'd pay 20 if they left me alone and never contacted me ever again. I was assured that this would not impact my credit rating. After paying the 20 pound I swore I would never talk to these people ever again. Recently I was remortgaging my property and found that I couldn't get the mortgage provider I wanted. I spent 15 pound signing up to Experian and multiple hours trying to understand why my rating was so poor and it turns out to be Vodafone. They had added a defaulted account to my credit report and not removed it even after I paid off the account. Vodafone - I will never buy another service or product off you ever again and will never recommend you to another friend, neighbour or colleague again. I can assure you that this bad will is going to cost you more than the £20 you squeezed out of me. Thanks for the worst customer experience of my life. I will use this experience as an example of how not operate in business when talking to friends/neighbours and colleagues and ensure that behaviour like this is stamped out.