Business account closed for 8 days now-No explanation from FNB

On the 11th October my mother realized our business account is not making purchases on the App and declining card machine purchases. We called FNB and we were told we owe service fees of R498 therefore our account is frozen. We were told to pay the R498 and our account would work again. Payment of R500 was made on the same day and until today the account is not working and noone at business litigation or *** can tell us why the account is not working. We can't fix people's cars because our money is in the account that is not working still on day 8 of trying to get answers from FNB.