Very angry and annoyed

Hi... I am having thee worst nightmare with CELL C whereas I believe I am a loyal client... I haven't skipped a payment with my 2year contract when it was about to end I had 3 consultants call me for an up grade and I told all of them No thank you... The 3rd 1 told her that in fact I want to cancel. I don't work @ cell c to know the procedure if YOUu are canceling... A month later I got a bill from CELL C and I reversed it and sent an email to tell them my contract has ended... in December they charged me double the amount. Worse part is when I was taking a new contract I was told that everything is fine I qualify and took the contract month end of December now on the 4th of JAN 2021 my service has been suspended that I need to pay the previous amount before I can continue with the new contract of which I'm stuck yet a debit will go through... How do I pay for services that I did not use? They can see on their account that I did not use the data if there was a problem why did they not address it sonner. Now I'm afraid I'll get a bad name for sum1 who did not do his or her job in the finance department. I am so frustrated I'm stUck with a router that has no data yet they're going to bill me R780 on the 15th excluding the R680 of December. Where am I going to get such amount in a short space of time. When I do things I plan I don't just do them. Norwonder people commit ***** Coz if u r trying to be loyal they say 4 what. Very disappointed and stressed