ADT Fedility Security ***** stars

***** stars I have cancelled The contract with ADT Fedility Security but they still debit me. I have sent several cancellation emails they deny receiving them cancellation emails but anything else I send to them they reply meaning they receive. I have reversed and blocked the debit order but every month they load a new debit order with a different reference number. I call them they say I need to send a email can't cancel over the phone sent several emails still nothing.