RCS Loan **** billing

I took a loan to finance my vehicle RCS Auto in 2019 May with a 72 month term which was suppose to end May 2025. I have never missed a payment on then loan even my statements show the end date to be 01 May 2025 . After the last installment on 01 May 2025 I have a balance of R8274.00 I have tried on several occasions to get clarity am where the balance is coming from when ever I make a call to the them am told that people from RCS Auto are not available my account will be sent to them and I will be called back since the beginning of May I have been awaiting the call.