Debit orders without approval?

I had a tracking unit installed in 2019 and my vehicle and the vehicle was ******. After explaining numerous times eventually got the contract cancelled. They now after 2 years somehow think it is appropriate to debit my account with no approval from me and when you try and get hold of their accounts department it takes 5 different numbers still with no one to talk to or assistance from anyone. I would appreciate if someone can contact me, as clearly my call is not of importance, but taking my money is.