Norman Bisset & Associate sucks ass (*******)

I cancelled my ADT account 2 months prior to moving house and 2 months after moving ADT still went ahead and debited me - I had the bank reverse the Debit as I wont be paying for a service that I don't use especially for cancelling them...... Then comes along Norman Bisset & Associates claiming that I owe ADT money after sending them all the email proof they requested they tell me I still owe ADT...... In order for them to stop stalking me I paid them the invoice value - a week later they then send me a new invoice value which I paid as well - A week alter again they send me a new invoice value which I once again paid - today they call me to say they have a new invoice value.............................enough is enough they are sure *********** and *******...... they have been calling me daily (harrassing me ) for more money........ Every call centre agent agrees telephonically that I can see the invoice and paid value but this is the new value.......