Taking my money after I cancelled their services

Hi. Do not use ADT Security. They do not have a quick response to anything, alarm, panic, or even a cancelation of services. I have cancelled them in the beginning of August 2015 and since you pay in advance, I do not have to pay 1 September 2015, but guess what, they just took my money, after I have cancelled them. This is by far the worst security system that I have ever bought in my entire life. I will never use them again, I am done with them. They also refused to give me back the 3 months I over-payed on my radio licensing fees.