Billing for account that i do not know

I am so mad with their service, i had i contract with Cell C that i took 2 years ago, it expired in August in 2017, before it expire a lady by the name of Blessing Vukeya from Cell c called me for renewal i said no to that she instead offer me Smartdata 500mb topup which she said it will cost me R45 i said yes to that, she then said this contract will take over when my main contract expire in July, that is the only account that i had with Cell C.On the 20th August Cell C debited R89 in my account instead of R45, 20th September same amount was debited i then asked my bank to reverse the amount since i knew nothing about R89 that was not part of our contract.On the 04 October my line was disconnected without anyone calling me, i the called Cell C a guy by the name of Thabo told me that i have to contract and its been 2 years now they cannot assist me because its been long, he told me that i had to pay, on my birthday 5th October a guy from Cell C retention called i forgot his name i explained everything to him he told me that they will override or something i"cannot remember the word he used" the R89 so i only need to pay R89 and they will open my line, i did that but nothing happened my line was still disconnected meaning that guy laid to me by saying my line will be open, on the 10th October i made a payment because i was just tired emotionally of fighting with Cell C, I then call the same day informing them that i made the payment and i have even send my proof of payment i was told that they can only open my line after 24 hours once the payment reflect on their side, I then asked them to change my line to prepaid, instead of them resolving my issue i was told that the last debit order will be on the 20th October meaning i have to pay again for amount that i didn't agree on that lady only said she is not sure how much i they going to debit but they will debit, i the this morning they tried to debit R89 from my account but they found nothing, so they now massing up my account by creating unpaid debit order on my account, I am not sure anymore what the want from me, i want nothing to do with this service provider, i will not even recommend it to anyone, pathetic bad bad worse service i ever had in my life to top it being laid to on my birthday.