Handed over to debt collectors After Cancelling my Telkom Business Account

I opened an Business Telkom Account in 2016 and cancelled it in January 2019 (or tried cancelling it like 4 times). Telkom rep**** with the "automatic reply email" acknowledging receipt of my emails but still- they handed me over to the debt collectors after invoicing me every month for the service i cancelled.

Phoning them numerous times trying to sort it out didn't help, Tried cancelling the service online as Telkom gives this option on the website and still no luck.

Any help on sorting this issue out?