billing dispute

I have a query with rain and need it to be fixed ASAP so i can be able to make payments as soon as possible. I see I have an outstanding balance of R6880 which I am totally disputing. I kept calling in asking for my payment date to be changed to the 1st of every month because you had the wrong payment date which was the 25th of every month. It took you a whole 4 months to do so. I called to again informing you that you are not debiting still no 1 said anything I was disconnected and kept calling with no help, NOW I MUST PAY R6880 for a mistake and delay caused by you which is totally unfair on my side because I kept on calling even now i called but was not helped and was told the is nothing you can do because its a policy, how on a month to month. I had no services and won't pay that amount, calculate my pro rata then get back to me so I can pay the correct amount not the R6880 or CANCEL my account and forget about my money because this is daylight ******* I CALLED countless times. This one is on RAIN not my fault, I would appreciate someone to call me back hence now my complaint is going to be escalated plus the bad services i got from the agents I spoke to.