Bad customer service

I made a payment on the 30th of December 2019 of R365 to date the payment is not allocated, I called the call centre several times and I could not get assistance, everything I am asked to send a proof of payment, I have sent it 4 times already. Today I visited the store at princess crossing hoping to get assistance the cashier called the call center and I was asked to send proof of payment again, tried to explain that I sent it several times. I then asked the cashier of the way forward and she also shook her head and said she does not know what to do. Meanwhile I'm receiving payment reminder every day