money withrawn by capitec

on the 17 and the 18 money was debited from account from capitec, reason was that (account correction ) for 500 I went to Namakgale branch to enquire only 500 was reversed back to my account when I enquire about the other they told me that they will call me back they are investigating since march 2016 till date I never received any feedback, last week I decided to call directly to call centre they also promised to investigate and call me back on Wednesday even today I haven't received any feedback. What I don't understand is why are the debiting my account without any reference what is it that they are correcting that they also fail to explain