Voucher Mess costed me Hours

I received a R300 Discovery Vitality Voucher to spend at ANY Pick ‘N Pay store, as this was the first time I had received this, my fiancé and I consulted with the cashier working at the kiosk before using the voucher, she ‘punched’ the voucher code in and advised it only lasts 15 min and had expired (weird since the text clearly states that it expires on the 06/10/2017) and we would need to dial a USSD code to retrieve a new voucher code, which she couldn’t remember of hand. She then told us to go to the enquiries section, where we were directed to the “supervisor”, we explained the situation based on the false information the cashier had given to us, the “supervisor” sighed and waited about 3 min to tell us, she couldn’t help us, as she didn’t know the USSD code to retrieve an expired Discovery Vitality voucher. We were about to leave, as I was really frustrated when my fiancé suggested that we go back and inquire once more, we did that and suddenly we were accused of miscommunicating the situation to the “supervisor” and we were then advised to proceed to shop. As bad luck would have it the “supervisor” was our cashier, she was STILL rude and completely condescending towards us, and didn’t seem remorseful or even apologetic for what had just happened. We got everything we wanted and decided to use the remainder of the voucher next door at the Pick ‘N Pay Liquor. Worst service ever. When we got to the till, the cashier rudely said we couldn’t use a Discover Vitality voucher at a Liquor Store, so for about 7 or 8 min, we stood at the till, holding up the que and embarrassingly arguing about whether or not we could use the voucher. I was under the impression that I could use that voucher for anything, as I pay my Discovery Vitality fee monthly, and amount of R219 and that was given to me as a good gesture by Vitality, it’s not an EDULOAN or NSFAS food voucher, it’s a cash voucher. I asked her about 7 times to try and punch in the voucher number to process the sale, if at all it didn’t work, we would pay cash or leave the products behind, she refused on all 7 times. She eventually did punch the voucher code in, as I was walking away because I had had enough of the disrespect, and surprise, surprise THE PURCHASE WENT THROUGH. What was the fuss?! Such a horrible experience, over nothing or is it because we were using a voucher that we were treated with such rudeness and disregard?! Hell will freeze over before I set foot in that Pick ‘N Pay store again.