Cancellation Letter

I sold my vechile and settled my account October 2015. On 3 November I send request for a cancellation letter and was informed by Graham that it's not possible as I need to pay an outstanding amount of R4421. On 4 November I paid the amount and he confirmed proof of payment. On 8 November I again enquire about the letter and was informed that the R4421 was incorrect and I need to pay another R691. I again paid that amount on 17th November and again Graham confirmed that payment received. On 22nd November I again wrote a email to Graham and up to date no response. To say the least the customer service pathetic, totally unprofessional and I will never recommend anyone to MFC. It's nearly one month and MFC still unable to issue a simple cancellation letter. ..I do not even want to know how pathetic the service must be in other departments.