Poor customer service

Good day, I am writing this review with a very sad heart due to the level of service that I received from Palm Springs mall based in the Vaal. As a FIRST time user I installed the Shoprite App after I had redeemed a voucher as opposed to having used their USSD code as one of their options. Good well woow the app is amazing and i must say that it is indeed user friendly. Follow the instructions on how to redeem my voucher get to the till point and the cashier says ' how much do i want' now i am shocked cause the voucher says groceries and she talking about money but i politely inform her that i cannot redeem money but buy food. I gave her my token and the token reads 'invalid' she says I must go to the money market queue which again i must go back to the line and when I get there, the ladies want my ID number and thereafter they tell me that there is nothing they can do. Firstly they do not have name tags. This morning, I called your customer care and I spoke to Nombuso Ndebele whom I must say tried her level best to calm me down but again feel that her and her manager should have better handled my complaint. Firstly why is that you staff are not tried on products? My daughter slept without food yesterday as the voucher is all that I had and all to be told that I cannot use it and there is nothing they can do like really guys?? I call your call center with my airtime and spent 25mins if not more. can this issue be addressed and i want feedback.