Money deducted, airtime not received.

On the 4th may I purchased airtime, R50, the money was deducted from my account however, the amount was never credited to my cellphone. I sent my cellphone provider a mail, to check what exactly could be the problem. A week later they got back to me stating that i should clear it with my bank. I am very disappoint and the service received. Why is the bank application giving such problems and why are we not being notified if there are problems.

I want my R50 refunded!