Issues with my Telkom contract for over 6 months

I've been having issues with Telkom regarding my cell phone contract since last year, they didn't debit my account on the day that they were supposed to then charge me R 200.00 for not paying my account. i had to call them every month end to ensure that they deduct the money from my account, at first they did credit my account back with the R 200.00 they charged, i even had to change the deduction date with them from the 25th to the 31st (end of the month) but the problem persisted, I got tired of the monthly calls and getting no help with them and stopped calling. In January 2019 I received and invoice saying I owe R 2074.07 which was due on the 31st January 2019. I called them on the 31st January reminding them to deduct the funds and their call center operator told me the funds will be deducted on that day. The funds were not deducted on the 31st January, I called again on the 1st February 2019 to find out why they didn't deduct but i was told to pay the funds online on my Telkom online account, i went in and paid the funds but it still shows that I'm owing and the amount has gone up now to R 2487.21. The money i paid is still outstanding and they still charged me yet another R 200.00 for not paying. I've got a bank statement showing I had funds in my account on the date they were supposed to deduct and proof of payment showing the balance was paid after they failed to deduct. I'm now unable to cancel the contract online because of the outstanding balance and ill still be charged R 100.00 for a cell phone i finished paying in December 2018. I need this to be sorted so can cancel my cell phone contract with Telkom. I tired from all the phone calls and attempts I've done to sort this out. I feel like they are just trying to get more money from me by not deducting when they are supposed to just to add the R 200.00 to my account. Its exhausting. I need the R 2074.71 payment I've made to be allocated to my account and the R 200.00 added to my February 2019 invoice removed. I'll pay the R 200 for the contract and i need my cell phone contract which ended in December 2019 to be cancelled.