Please remove me from ITC and give me paid up letter

After being a good loyal customer to Mtn South Africa and paying off my account with them more than 2 years ago they decided to list me. I've been asking for my paid up letter from their customer service store but they said they will email their collections department to remove me from ITC and give me my paid up letter because my account was fully paid. Till today I'm still waiting for their action /response. Can someone please assist me with this issue and give me my paid up letter.