Mixtelematics are **********:debiting customers accounts with no manadate

I am so fed up with this company still trying to debit my accouny even after it has been paid up in full. I even received sms confirmation to say account has been closed. Statement is on 0 zero balance. They are still trying to debit my account. And then i receive phone calls saying my account is overdue. Mixtelematics are ********** who are taking peoples money without their permission or mandate. They are *********. What they are doing is *****.