How can I pay something that I don't have?

My car was involved in an accident last year October 2018 and it was written off. So I phoned the cartrack to come and remove their device, they told me stories and they did not come but they keep on deducting my money on my account then I decided to change the bank. Now they keep telling me that I owned them more than R2000 and it keeps on increasing they all said they are going to black list me. Please help