LONG WALK TO GET A PAID UP LETTER!!!!!WORST SERVICE PROVIDER IN TELECOMMS

Heading into the 4th months now and cell C does not want to release for me proof of paid up letter and unnecessarily affecting my credit records. I have been seeking finance for a vehicle and other things and they cant approve me and reason being cell c this is affecting me to an extreme and all the time i call they tell me they are still busy with the case well over 3 months even today i called same story. i want this removed like yesterday and if not done i will seek legal advise cause the adverse effects on my credit report are untrue and you guys are failing to resolve it.