being passed from pillar to post

I had two loans with Capitec and was handed over to a debt collection company. I have since settled both loans and suddenly no one wants to help me. I have sent both proof of payments but they still have not updated my credit record or provided me with a paid up letter. When I call the debt collector, they refer me to Capitec and Capitec refers me back to them I am basically being passed from pillar to post. I have tried disputing this with Transunion and Experian but none of them can help me without the paid up letter. I am stuck between a rock and a hard place!