Broken Hisense promotion promise at Game Cresta

I saw a Hisense promotion at Game Cresta offering a 100” + 40” TV bundle for R34,999. I went to buy it on Tuesday, but the system didn’t apply the promotion, and the store said they couldn’t override the price. I returned on Sunday, only to be told the promo had ended on Friday. Since it wasn’t my fault that the system didn’t process the promo when I first tried to buy, the salesperson assured me that the Hisense representative would arrange a R3,000 voucher instead of the 40” TV as that will be the new promo. I agreed to that and went ahead with the purchase but I have not received the voucher and the salesperson sounds unsure and says he’s waiting to hear from the Hisense representative. The TV hasn’t even been delivered yet, and at this point, I will not accept the delivery without the promised voucher. If this issue isn’t resolved, I’ll have no choice but to cancel the purchase altogether. This experience has been extremely disappointing. I trusted both Game Cresta and Hisense, but they are not honouring their promotion promise.