Account closure issues

I have been trying to close my account for 2 months now, I paid up the amount due in September and requested for the account to be closed, I phoned, emailed etc etc, I just keep on getting statements and amount due with no one assisting me in closing my account!! I see a lot of people struggling with this and I think it is time to intervene. According to the last person I spoke to he was going to get them to send me a settlement letter and still I have no letter, no response but you are quick with the statements and collection letters. I just want this account closed.