Disheartened

My purchased a R500 Dischem voucher from her banking app as a gift for me to start shopping for my unborn child. When I got to Dischem Centurion Mall I asked the customer services lady if there was a way I could purchase a Gift card worth R500 so I could shop as and when I needed stuff. She said she advises I use the voucher partially instead and I would be able to get a new wicode for my balance. That was last week Sunday I spent R117, today 9 July 2021 I went back to the same Dischem to find out how I can get a new wicode so I could make my purchase,guess what the same lady said. The balance has been forfeited and I should've used all the money. *** customer service is that? I don't work for Dischem I couldn't have opposed her statement last Sunday but to come back and the same person says something this contradicting and have cost me R380+ I am beyond heartbroken, I cannot believe someone would do this. She shouldn't be giving customer service.