bad service

I rented a car last year in October and kept it for 32 days. initially the rental was for 2 days and I kept extending during that time and they kept deducting money from my account during after I returned the car they kept calling saying I was owing R10000 till they handed the account to debt collector's cause they couldn't see the payments I sent Marcelle my bank statement with transaction reflected and they have not sorted out the issue and no one has contacted me. the other issue when I took the car it had scratches on the bumper and they said I must pay R4000 to fix them which is reflected in the invoice I requested. please help I can't do my things because now I'm blacklisted for payments I had paid