Telkom incompetency ruining my life

I bought a router with Telkom, a day later I cancelled the contract as they offered me 10g which finished the same day, whilst my Vodacom 10g last for almost a month, immediately I went to the shop with the router to cancel the contract and to pay what is due, I was advised I can not do that transaction in the shop they will create a case someone will come back, I asked about my cooling period they acknowledged and promised I will receive a call from the relevant department, no one called or followed up with me for three months, after 3 months I received a call which I missed as I was in a meeting, I called to follow up, they said a case is opened they will call me again, then I stopped the debit order from processing with hope someone will call me, then realized my name was in red at credit bureau, I called them again I was given a settlement which I payed, later I called to check the account will be closed to find out that the account is still active, I asked again what is happening I was told the account is in areas and I have to pay more money to close the account, I refused as it was lots of money, I open another query which a supervisor promised to help me with, I called again to follow up, I was advised the supervisor never logged any call, so I was back to square one, the next thing I know I have a default on my name