Unauthorized debit

I once had a car maintenance contract with innovation group n it was cancelled a year ago as I no longer required their service and contract was expired. So all of a sudden they came back to debit my account after a year of expiration of a contract and I called them to ask why now again n the consultant can't even explain why and she told me that she will ask the manager and come back to me b4 closing of business and it's now 4 days and I'm still waiting for her call