A withdrawal amount that includes decimal values may, in some cases, round down when the balance is shown (i.e ZAR 51.23 appears as ZAR 51). This is limited to certain currencies only.
The amount specified remains the amount withdrawn, and the balance displayed is a visual bug that does not represent the actual withdrawal.
If this does not describe your issue, please open the Transaction history in your Personal Area (PA), select the withdrawal item, and choose Get Support to open a ticket.