Overcharging clients

My account with ADT is NKO01339 and my contact is ********** 588. In July 2017 I logged a call with ADT call centre for fixing my beams, a technician came to see what the problem was but failed to fix it, he left and I signed the slip that he came. Third day after he promised to come and fix the issue, he did something but the problem continued, I logged the third called by still nothing happened and on the fifth time he called me to make arrangement to come and fix the beams problem and he managed to fix them until today they are working perfect.

My problem is ADT charged me for four calls logged on their system for one problem that they failed to fix in the first place and now they are busy trying to debit my account for R392.00 monthly instalments instead of debit the credits that they took in my bank for incompetency.

And they are threatening to suspend my account while they actually owes me.

This is not the right way to make money out of black South Africans they should have billed me once for a call out and fixed the problem there at first instead of coming to my house four times with success.