Unauthorized deduction from bank account

Discovery Insure took money from my account, unauthorized, after I cancelled my insurance policy. The theft is allegedly a penalty for not making an appointment to remove a tracking devise from my vehicle. My inability to make said appointment on their platform was pointed out to them on 27 November 2020, with a request to call me an make an alternative arrangement. This was ignored. I have been trying to explain this for two weeks now, with no success. It seems that nobody there is interested or able to read and digest the history of this.