There billing structure is a disaster

I have an account with geen n richards which is under African bank. I tried buying a house then I found out that my acc at African bank is in arrears with R10000. I paid the amount immediately then I went to ABank in few days then I found that my arrears are R1600 then I paid immediately again after few days I went to check n find that my arrears are R300 then I paid again. mind u every month instalment runs on time. then i received my statement this morning I have an arrers amount of R1300. how does the acc hav arrears while I paying every month. and this thing is ruining my credit scores as I am trying to buy my family a house but they keep on making my name bad while m paying every month and debit order not by hand. could you please find out for how does this shift bank works as I've tried very hard to speak to them but they never listens to me and their stage are very ***********. as for their accounts they suck big time. how can a person have arrears while they r paying their acc on time and the exact amount. I am tired of going to Abank every day to ask about the same think. I want my name clean as I am not a bad payer. I paid more than R14 000 in a month to Abank but with n