Smart Shopper Voucher

Just now at 19:34 on Saturday 29.08.2015 I purchased a carbonated soft drink, I wished to use a smart shopper voucher that is valid until tomorrow that entitles me to 3x points on any carbonated soft drink. Ncediswa had no idea how to process this and had a very bad attitude in telling me that no u cannot use it. I said to her to please scan the voucher she hissed and tried to and then said \no sorry I can't help you come back tomorrow for the day manager to assist"as I too work as a service provider I was appalled at how badly she handled this and to aggravate it I received no apology or any effort from her to compensate for her utter rudeness. This voucher expires tomorrow and I was told I could not use it? How is this a service to me as the customer? I hope you will respond to me after this weekend"