ADT accounts department unwilling to assist

I enquire with adt on an amount that I over pay them, on my account it does not show and nobody at their accounts department can find the amount then I send a mail on the 4th of February to ADT accounts department, on the 6th I resend then on the 10th I resend with the account information from the bank showing the second amount of R1322.97 that I paid twice. Today I phone to ask about it and they received the mail but I got no answer from nobody, they were going to contact me back but not sure if it is going to happen. I phone them to add an extract outside alarm, still waiting on someone eventhou an appointment was made with me, I contact pope alarms and someone was send to me to help so maybe I should get my money overpaid to them back and go to another alarms company, my complex got 10 houses that use adt maybe I should advise them all to leave adt as they do not seem to need any business they got to much.