Contests are governed by state law, and they're the contest's rules spel out how it's supposed to work. Here, you write there was no "small print" until you asked for the ipad.
While it's possible that a Small Claims lawsuit, or the threat of one, would make them send you an ipad to restore your goodwill, or get a Small Claims judge to award you one, I don't think that would happen. They used the word "win" which implies a contest, not "get" or "receive" which implies that "liking" them on Facebook would be enough to get the prize. I don't think anyone could reasonably believe that they could win a prize like an ipad by just a "like" click.
Avvo doesn't pay us for these responses, and I'm not your lawyer just because I answer this question or respond to any follow-up comments. If you want to hire me, please contact me. Otherwise, please don't expect a further response. We need an actual written agreement to form an attorney-client relationship. I'm only licensed in CA and you shouldn't rely on this answer, since each state has different laws, each situation is fact specific, and it's impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue.
Each state has laws that govern contests and lotteries and require certain mandatory disclosures, such as how many prizes are available, how the winners are chosen, whether a purchase is necessary or increases odds of winning, etc. it sounds like this company likely did not conduct the lottery properly, but your remedy would be to sue in small claims court. Honestly, it is likely going to cost you more to pursue that than to buy an iPad.
The statements and views expressed in this posting are my own and do not reflect those of my law firm, are intended for general informational purposes only, and do not constitute legal advice or legal opinion. This information is intended for informational purposes only and should not be relied upon without independent consultation and evaluation by an attorney. This information does not create an attorney-client relationship. Please consult an attorney if you have any questions about the subject matter of the information above.