Unbelievable...it happened to me again!
I went to the store again yesterday (to buy the milk I forgot previously), only to find the store owner regretting the previous sale.
As I am a kind hearted person and didn't like to see him so upset, we came to an agreement and I returned the original item.
Somehow (and I'm still slightly spooked how this happened) when I got home, I discovered something extra amongst the groceries...
Oooh spooky!