Bad service. No care from pick n pay

I bought groceries at pick n pay bluewater bay port Elizabeth with gift voucher it was declined but when I call customer care they say voucher was used that day and I had to pay cash for it R287.52 paid twice. My number is *** I used over R60 trying to resolve over the phone called customer care I was supposedly transferd to voucher department and was on hold forever. Called the store person who answered had no empathy at all refused to give her name just asked what do you want? Call disconnected and she did not bother calling me back. Such poor service.Why did they not investigate the decline in the first place . I had to call customer care my self as a customer.Cashier name Ntombodidi Mavikela transaction time 10:03 date 18 March 2020.