Worst service and customer support

Worst experience I have ever received from a company, I cancelled my contract last year july, two months later I received a payment instruction of 3800 for behind payments and was threatened with blacklisting, I called cartrack and payed the 3800 and once again said I cancel, the women agreed and said my cancellation will be processed and go through, the following month they debited my account again, after phoning them and asking why they have debited me they said they are sorry they gave the cancellation through to someone who does not work there anymore and will reassigning it. Its been almost 6 months after this and my account is still being debited and each time I call I get a different story. This is really pathetic and the worst service I have ever experienced.