Being Billed for services not recieved

I received a notification from tracker and called the call center and asked them to ensure that they don't debit my account in March as I have no standing contract with them. Tracker promised to look into it and ensure that my account dose not get debited. My account got debited and there were no funds so my bank charged me a dishounered debit fee for an account I did not have. Secondly Tracker have sent another notification to debit my account even though I do not have an account with them.