Made to Wait Forever Only to be Told Voucher Does Not Work

I was made to wait a very long time to claim a voucher from one of the spins that I won from the Checkers app where if I buy one coke, I get another one free. The voucher could not be accepted by the system when the cashier tried to load it. I was sent from one cashier to another to assist in loading this voucher until eventually I got to the manager who also tried to load the voucher but she also could not do it.

After being made to wait a very long time, the manager just told me it doesn't work. No explanation, no apology and I just walked away. Mxm! Sies! Besides having to wait in ridiculously long queues as is always the case when I go to any Shoprite, and the complete waste of my time, the service I got was not good, unfriendly and unprofessional! But what do you expect from a retail like this that treat Black people like this?