Poor Customer Service

I returned a pair to Nike Air Force 1 sneakers today (27 November) at Sportscene Cresta. The option was cash return or a online gift voucher. They did not have cash, so I opted for the gift voucher as I was assured by the assistant that it will take 5 minutes to activate. I decided to shop in the store and then use the voucher to purchase some clothing. Almost one hour later, it still did not send through the voucher. The store assistant called the head office to be told there was a glitch, but it is all sorted (this was after the first 30 minutes. By one hour, I was irate, and the store assistant called again, and was told I should receive the confirmation. I was truly upset as the clothes I wished to purchase was for a trip I am leave in the morning for the rest of the week. I decided to complete my shopping in the mall, and told the assistant I will be back, and hopefully this issue will be resolved. I unfortunately was not, and left the store stating this is poor service (to be clear, not from the store but head office, or whoever deals with these vouchers). The SMS notification was finally delivered to my phone at 17:48, almost 4 hours after it was meant to.