ADT refuse to update our account

This is yet another report, as the previous one in March went unanswered by ADT!<br> <br> We cancelled our service with ADT early 2014, and the account is paid up. Despite this, we continue to receive monthly statements demanding money that was paid up long ago.<br> Each and every time my wife calls ADT to sort this out, the call centre is extremely unhelpful, and always tries to palm her off onto someone else.<br> I want this sorted out this week!!