Bad onions from the corner shop

I was in the middle of cooking a Spaghetti Bolognese last week and a spot of bad planning on my part meant that I had run out of one of the more important ingredients.  There weren't any onions left in the vegetable rack and as luck would have it all the supermarkets were likely to be shut (5mp on a Sunday!).  There was only one option left open to me.

Off I went round to the corner shop to see what they had.  I vaguely remembered seeing a fruit and vegetable section there before when I popped in for milk or something.  Now I don't often use the corner shop - only in an emergency and these occasions are few and far between.  The reason for this is mainly because they're too expensive and quite frankly, it's not all that pleasant in there.  There's a kind of musty odour about the place and I'm not entirely convinced the place gets cleaned very often (if at all).

They had onions though, half a box of them in fact.  So I quickly rummaged through them and pulled out a couple of decent sized ones.  I thought I might as well get two because it's always handy to have a spare onion and I wasn't sure I'd be going out to the shops the next day.  I tend to choose try and find a firm onion because they tend to be fresher but there really wasn't much choice here.  They all seemed a bit on the squishy side, but they didn't look bad or anything so I figured they'd be fine for a couple of days.  The man behind the counter charged me 50p for these which personally I thought was a bit on the steep side, but there again, you expect to pay a bit more for the convenience factor don't you?

Back to the kitchen and I'm preparing our meal and I sliced into one of the onions only to find that it was all bad in the middle.  Okay I thought, so it's a good job I bought two and sliced into the second onion to discover exactly the same story.  So basically I'd just gone and bought two bad onions from the corner shop for 50p.  Bit of a waste of money really when you can get a back of decent ones up at the supermarket for the same price.  I was pretty cheesed off with this, but somehow managed to cut out the best of both onions and somehow scraped together enough to cook the Bolognese - just chuck in loads more garlic, it's the same family and no one will know the difference!

I guess I should really have taken them back and either exchanged them or got my money back, but the prospect of standing there in the shop slicing up onions until I found one that wasn't rotten didn't entirely appeal and doing without wouldn't have worked either.

It just irritates me that basic standards in convenience shops are so low.  If the large chains were to let their standards drop they would go out of business very quickly.  The little shops seem to get away with a lot more though, presumably because they're open all hours, every day.  What would you have done in this situation?