Aarone, it would be pretty unlikely you could hold them to that price. Its likely your reciept was an automated responce, and no ones looked at it yet. Hopefully they will give it to you anyways though. Most stores have in their ads's particualarly newspaper ads that they're not responsible for misprint prices,etc. Many websites have similar protection clauses incase of hackers, accidents, etc.
Good luck though, hope you're able to collect it.