virgin Mobile Account

My Husbands Virgin Mobile contract ended and he contacted them by phone to inform them he wasnt renewing the contract this was april may time.The person he spoke to said that there would be on final payment to be made the next month.He paid that then he recieved a letter from Moorcroft Debt collection saying that was an outstanding amount to be paid.Okay we paid that in good faith.A couple of weeks ago he recieved yet again another letter for double the amount.We wrote to Moorcroft explaining that he cancelled the contract and as far as we are aware the account is paid up.They said that they would get back to their client.He recieved a letter yesterday from them saying they had been in touch with 02 and they say they have record of the contract ever being cancelled and they will continue to bill him every month.I was with my husband when he made the call.In hindsight he should have taken the name of the person he spoke to and asked for a conformation email but he d been waiting so long to talk to someone and when he got through he couldnt understand the person he was talking to he doesnt do well with phone calls.