DStv - On air - cancelled decoder purchase yet they still debit my account

Cold called without any authority. They got my details from DSTV who has no permission to share my details. They insisted on selling this upgraded decoder and despite me asking many time if it is dual view to serve us they still sold us a product that is not dual view. Advised On Air immediately. They refused to cancel until we pay R350. I asked for the details to pay so they can collect and cancel. They said they would investigate and revert. Despite numerous engagement and follow ups no-one to this day provided the details to pay the R350, no-one collected the device, it is still lying just like that in the box waiting for them to collect yet they debit my account, despite me cancelling the debit order and now they threaten me with negative credit ratings. I have tried to reach them via their whatsapp line and by email so that I have records of every word being exchanged. They simply do not respond ever. They also charged more than what is on their website. The operator said it was just that the website had the old rates and had not been updated however the website still has the same amount since then. Reported these to the Ombud of CGS.