Charged after policy Cancellation

I canceled my ADT security subscription on the 15th of August after it took ADT over 30 minutes to respond to a security incident where a group of guys broke into my property. Another local security company used by my neighbours responded in less than 5 minutes thanks to my neighbours, while I was being directed from pillar to post by ADT. After the incident, I then moved to the security company that was of help. At this point ADT told me I still have to pay for the coming month since their notice period is 30 days. They've however continued to deduct money from my account for the past 2 months. I have lost all trust when it comes to ADT, I have been a client of theirs for about 5 years now, and I would not recommend them to anyone.