CONTRACT EXTENED BY THREE MONTHS

I have been communicating with Petersen who couldn't read their statement as they are saying I am owing them R15 000 more from the contract signed. My concerned is how many blacks are being ****** because they don't send statements or call for the reminder of the non payment. What is shocking for me is the R40 000 I paid and they didn't recover the arrears, they were thinking I wont know that I signed a 72 months contract. They have done purposely for not sending me statements knowing very well that I wont remember, moreover with the amount that was outstanding if a customer has not payed the very same months, I was owing them R381 000 and the never said a thing and even the month they said I didn't pay I know myself that there was no way but unfortunately I don't have proof of that payment. Had they called to make me aware of the non payment, I would have had the receipt that I paid with as proof of payment. I am very disappointed by Standard Bank