"I think you'll find the S3 is still far more powerful and capable than the iphone"
Exactly how is this related to your complaint about the iPad 4?
"how can my uncle's limited knowledge tell the difference when he looks on the Apple site and can only see info on the new ipad showing the 4th gen and no info at all about the 3rd gen? "
It's up to the buyer to be educated. Blaming Apple for the fact that you're uncle is not is egregious. Too, if you're uncle knew that the latest product is the iPad4 - you know, the one with the totally different connector - and he decided to buy an older product, he should accept responsibility for his actions.
" I don't think he'd get it back and to the store within 14 days. "
A bold assumtion on your part. The fact that neither one of you tried to solve this situation as recommended, was your personal choice.
"Sure you can say send a voucher/money which is rather impersonal "
I never said anything of that sort.
"You're also assuming the store intentionally deceived my uncle, which is not true..."
You implied the store deceived you - I did not infer it.
"Funny how the mods decide to ignore such obviously useless posts."
My thoughts exactly.