I received a huge bill from ADT claiming I owed over $200.00 and I was past due. I called to inquire as to how this happened and was told that they were now billing quarterly. I canceled my service and gave them my credit card number to pay for the one month I owed. They began to call me at least 10 times a day, 5 were from collections, 5 were from someone trying to talk me into keeping my service. This went on for over a month. Most of the time they would hang up if I answered. I repeatedly told them to stop calling me. It would start at 7:00 am. They even called on Sunday. I called them again to reiterate that I cancelled my service. This time I was told they would cancel it in May. They claimed that I did not give them my credit card to pay. I told them to send me a bill. Now I get a bill that is double the amount they claimed I owed because they are charging me for June through August!!!