Poor customer service

I had the worst customer service in shoprite middastad mall,I have purchased a few things and wanted to pay with my TUYU voucher, the cashier didn't know how to processe the voucher, she then called some1 else, and she said out load that she also didn't know how the voucher work, but there was no effort to assist me, they then said that the system is offline...they were *********** of doing their job..I also work in retail, and customer service should always be on top..managers please upskill your staff on the till,so that they can assist customers with confidence, and also improve your customer services in your store...I don't think that I'm the only one using this TUYU voucher, are you guys aware of this kind of voucher,if yes, than please train all the staff who is working on the tills,cause I don't want the next customer to be inberressed the way is was today..