Netstar cancellation

My car was ****** at the end of August and Netstar was not able to recover the it - they said they were no longer picking up signal on the tracking device. I tried to cancel my contract because they continued to debit my account despite my car being ****** and when I contacted their call centre the consultant(s) were giving me the run around. I’ve also tried to contact them on their WhatsApp chat and Twitter account and I still haven’t received assistance.