horrible service

I got a contract sometime last year with Telkom where by from day 1 up until i decided to cancel the contract last year November the service was so horrible to a point i decided to pay them. i went to the store last year and asked the procedure to cancel the contract i was told i have to paid an amount of 485 for router for me to cancel i did that then after a week or so i went to the store to double check if the cancellation is done and i was told that is done i even paid more because now telkom owes me 300 then i said to the but they cant refund it to me unless i buy data, i said i don't want anything to do with them at the moment will think about it to my suprise now Nu debt Management the send me an sms saying my account its in errors, how come and what kind of services is this. Telkom doesn't know what theyre doing