No amusing ones happened to me personally, but I was chatting to the delivery man about this kind of thing a while back. His most amusing example was that a middle-aged lady who had requested a pack of peanuts had them replaced with a copy of "Nuts" magazine.
Click the no substitutions button. Seriously. The software gets a bit incredulous ("You have clicked the no substitutions button. Are you really really sure about this?") but it'll accept it in the end.
I've had lemons instead of lemonade ...... like, I should make my own and was being lazy or something, notwithstanding the doubtful fact that there wasn't a single bottle of lemonade (or indeed Sprite or 7Up) in the whole store.
I once had a Christmas cake in place of eggs - I suppose they assumed that was what I was going to use the eggs for
Also I once ordered some New Zealand Sauvignon Blanc wine, and they said they were unable to find a substitution, so delivered none! I find it hard to believe that they couldn't find another bottle of white wine in the whole store....