No updating payments for months

I have been paying my account every month now at the end of my contract the problems start they phone me 5 times a day asking why i dond pay i have phoned the haed office spoke to Zachary telling me i am not in arrears and that they did receive all the proof of paymens i send he is escalated this matter please i have send all the proof of payments even a R2040 payment to settle this account i need feedback as i get no response on email. I'm so frustrated where is my money i have send all proof of payments to ***ca