Bad service/Lack of information

My family visited the PnP at Liberty midlands mall.My grandmother collects an old-age pension&since we were at the mall,it was convenient to get her a few items(using her SASSA card) as well as collect her pension payout.We got a few items,and decided to join a queue.We stood in the line for a while (which was not an issue).The issue however did arise when we got to the till,after standing in the long queue only yo be told that my gran cannot use her SASSA card at that till-point.& we could only complete the transaction at one till-point(at the end of the store).How absolutely ridiculous?We then went to that specific till-point.Both my brother and i looking for any visible signage of pointing which till-point to use.There was absolutely NO INDICATION that only one till was operational for senior citizens.Since when is it ok to inconvenience customers?Especially senior citizens? To top this of,the cashier was rude!As we had put down the items to purchase on the counter,the cashier SHOUTS , that her till was for pensioners only.In the future we will use stores that actually value their customers.It is sad to see PnP deteriorate to this level.I don't advise anyone to shop at PnP .