Unprofessional service and non return of money!

What unprofessional service! Mr Price had incorrect discounts app**** onto their online shopping portal (which had nothing to do with the customer!) so we processed our orders and a day later received an email stating that the order had been cancelled due to an error on their side and that they were going to refund the money we had spent. We waited and received another email with a voucher to spend at Mr price. We have emailed requesting a cash refund but somehow we keep getting a response by what seems to be a bot. First of all, the error was on their side, not ours, so it's all good and well for them to cancel the order. BUT, return the money in cash which is what we used to pay for the products, we shouldn't be locked into shopping at an unprofessional store by offering us unwanted vouchers. This is unacceptable and we are actually quite disappointed in the service. The most annoying part is that for a friend of ours who was in the same predicament, had her money returned and here we are stuck with a voucher we don't even want to use!