Bad service received at Rocomamas Mall of the south

I'm very disappointed with Rocomamas Mall of the south, the food was good but I'm not happy with the service I got, I wanted to pay using a voucher and after making me wait for like an hour to pay I'm then told they are not registered to accept that kind of voucher, while at my bank its one of the registered restaurants we can use the voucher at...so now I had to pay with cash which I was not prepared to pay with, that was such an inconvenience since it was not even my fault that their system is not up to date.