Actually, the wording wouldn't be "why can not you get me some ice cream". It would be "why can you not get me some ice cream". Just because a contraction is used does not mean that the word and not are next to each other.
I should be dead about a million times over, for all the chain letters and emails and texts that I've received and NEVER forwarded one. So I find this HILARIOUS! They are like Blackmail, Guilt, Fear letters.