Plankton.mobi do not refund unused credit on card

I attended the Mumford and Sons live concert in Pretoria on 6 February 2016. The concert organisers made use of a cashless system for buying merchandise and refreshments. <br> <br> Concert goers had no choice but to make use of the system. On the card it is clearly printed that unused credit can be refunded via an ATM transaction. The card number needed to be sms'd to a number and instructions would be sent back. After sending the sms a response is received stating that these instructions would be sent back in 2 weeks. This never happened after the prescribed 2 weeks. I tried sending the sms again another 2 times and still nothing.<br> <br> I find this to be completely unacceptable. It is much like theft. Plankton.mobi pledge to return money to customers but do not do so, they just keep it. I plead that event organisers take note of this and in future they should not use the services of Plankton.mobi.