Jim,
In some cases it is people being unreasonable. But I have to side with Paul. I have shopped at this P’nP plenty, it’s 2 minutes from my place. But eventually I had just had too many unpleasant experiences there & I don’t use them anymore. The cons outweigh the pros. I have shopped at other P’nP’s without an issue. The Norwood P’nP is in a league of it’s own. Without a doubt, their staff are the most unhappy, unhelpful people I have encountered. 
I use the Norwood Spar & Woolies for all my shopping now. At the Spar I can do all my shopping in a few minutes, have a nice friendly chat with the super-efficient cashier on the way out, and there’s never a payment problem. Way I see it, my time has value too. It takes an average of 30 minutes less time to do it at Spar than at that P’nP (assuming no payment problems at P’nP). On those numerous occasions that P’nP is having a payment problem, you save 60 to 90 minutes by doing your shopping at Spar. When you add that time up, what you save by shopping at P’nP doesn’t really matter.
That’s my 5 cents:)