Disgusting service from Mediclinic collections department

Cape Town Mediclinic collections department is the most disgusting department! They just listed me on the credit bureau for non payment even after paying them for the past 3 months, the last payment being this month. I have been sending my proof of payment to a person by the name of Sindiswa Nongogo but no acknowledgement was received and they have now listed me on the credit bureau which now trashes my credit score and the chance of applying for a home loan or any type of future credit. This is disgusting and they need to take full responsibility for trashing my name with false information