Cancelled data contract but debit orders dont stop

Cancelled my mobile contract by giving 2 months notice. The debit orders however does not stop. I have spent hours dealing with different people but nothing is resolved. They have given me a case number (***2) but that is as far as it goes.<br> <br> I cannot believe that a listed company can employ so many *********** people. Maybe they are all waiting for their retrenchment packages