Incorrect amount of levies charged and bad service

I moved out of Afcho Properties (building Frank n Hirsch flat) last year end of September and to my surprise i was charged levies for August, September, October which amounted to 1100, i escalated to their finance department and they reversed the amount to 735 and my other concern was that i was not even there in October, regardless i paid the money, now im harassed by their dept collectors saying i must pay 1100, i called their offices on ********** / ***and no one is willing to assist, yet they sent my name to ITC and listed me as a bad payer.