********* behavior from ADT

Of lately they deduct any amount from my account. They took R682 without any notification and it is not the agreed amount. Where does it come from? We have two accounts and they are constantly double debiting on an account we told them to change the bank details. We keep reversing the debit order. This has been communicated to them and we have emails to prove that. Please sort this out. If not as soon my 2 year contract ends I will not renew it.