Telkom ********** billing

I made an online purchase , received the device 23 October 2018, I cancelled the contract on 26 October 2018 within the 7 days cooling off period. The device was never used and Telkom has since collected the device and yet continue to bill me for usage. I have spent hours trying to resolve this and lodged countless disputes and none have been attended to. Telkom is useless and I will be taking them to Small Claims Court.