*****ing my money

I cancelled my contract witg ADT in November, and they are still deducting the monthly intallment. I went to the Vanderbijlpark office to get a letter, in order to prove that i am not behind on payments (as this is what is reflecting on my credit record now), which they provided and yet today another debit went off, which i AGAIN have to reverse.. so now i will have it show up against my credit record again. ADT is probably the worst company i have ever come across and I honeslty hope people will stop using them as a security company. They are *******..