Unauthorised debit

I have gone through a rough 4 months having closed my company due to the postal strike and am in areas on my fnb personal loan. I have a payment arrangement on it for R1000 per month which is all I can afford to pay on it until the end of May. Even though I have met this payment arrangement on Friday an un-authorised debit of R819.19 was taken with the reference PERS LOAN ***43 150306. I immediatley contacted personal loans and requested this transaction be reveresed since I need to feed my family and this is not part of the arrangement. I was told it will be reveresed within 48 hours and I requested a reference no for the call, I was given this TCCPDCMXAS***.138937, This made me dubious as it seems to be designed to be impossible to remeber and I immedialtley transfered the remaing R400 out of my account for safety. The transaction has still not been reversed as I expected nor have I recieved any contact about it. If this transaction is not reversed I will NEVER keep money in this bank again since I cannot trust it and frankly I am getting extremely upset about having to resort to hello peter in order to recieve service.