Lying about account

I called the Credit Card department yesterday to cancel my credit card and spoke with Milo (spelling could be incorrect) I asked for the account to be closed and I believe my balance is zero. She then confirmed my Balance on the account is Zero and they will log the required process to close the account and should be done in 24 to 48 hours and I considered the situation dealt with. Later the afternoon I received a call from one of her co-workers informing me the account will not be closed as I now owe R500 and something on the account for interest all of a sudden. Why does it change so rapidly from I owe nothing to now I owe over R500 on the account? I spoke with the Smart Spend Loan division around the same time and they immediately told me when I requested for the loan to be closed eventhough balance showed R0 there is an outstanding amount of R300 and something of interest on the account before they could close it. Why could they do they job correctly but the credit card division couldn't? I then requested the recordings to be sent to me and they said they can not send it to me I must go to a branch to get it. Very unhappy with FNB since they ignore \Premium"client calls."""