Terrible service

I sold my house and sent a request to cancel Adt services in July. In august they deduct and I call in to ask why they told me I should have sent an email. I send the email on the 11th of August and two weeks after that am told that are working on the request. Instead of a cancellation letter ADT deducts again. Two premiums paid for a house I do not own anymore. Why? How do you decide to do as you please in my account! Your service is terrible