Discovery Mall Disgrace

One has to question why discovery has a voucher option in their discovery mall. If you do not (wait a week or more to receive a mall voucher, you get to the till and once the voucher number has been submitted, the cashier tells you sorry sir there is no sufficient funds. Well that is impossible right? Apparently not. Discovery send you the voucher but does not load the funds. And as the cashier said: \This happens often