Unauthorized debits after canceling the services

I have been paying for the cellphone insurance of the contracted cellphone that I paid in full in 2021,which was for 2years .when fully paid I went and cancel the insurance in one of the outlets, still it continued to deduct, went back again and they gave me the email details to do it myself I did but yet it still continued. I went back to the other outlet and laid a complain nd I was told they will do it themselves on the system. But to this day it's still deducting 3years later..