Rude staff - I will never go back

My spouse and I were at the Pick n Pay in Woodmead and after completing our purchase for groceries, proceeded to the kiosk to buy a packet of cigarettes. We had a discount voucher from the Pick n Pay brand match promotion (which we have used previously to purchase cigarettes). The cashier at the counter was down right rude in telling my spouse that such does not exist and that the voucher cannot be used. I was not at the counter. Now whilst I may understand that terms and conditions apply to various things, I do not appreciate the inconsistency and the plain rudeness of staff that brought my spouse to tears. Such matters can be conveyed in a polite manner to the customer. There is no place for poor quality service. It is not my first instance of rudeness and as much a I do all my grocery shopping in that Pick n Pay, I will now move to another supermarket (as there are many others) and will never go back to that store. Frankly I am disgusted with the store.