What law does that break? It seems the same as any other infomercial product's claims: "If this product isn't the best widget you've ever bought, or you're not completely satisfied for any reason, we'll refund your money"
In this case, if the prediction is wrong (not the best widget/customer not satisfied), they can get their money back.
Come to think of it, the prediction claim isn't much different from most test prep higher score guarantees.
In conversation with a UK lawyer it would be deemed illegal as you are misrepresenting the "product" for which you are taking money. It's effectively the same law as covers items sold where they are clearly intended for a particular purpose, but then try to claim no guarantee that they are, in fact, fit for that purpose.
UK law is very broad in its protection of consumers against "products" that are presented in a deceptive manner.
"covers items sold where they are clearly intended for a particular purpose, but then try to claim no guarantee that they are, in fact, fit for that purpose."
You mean like just about every software license agreement in the world? ;)
So basically... If there is no "insurance" so that mail a notarized copy of the birth certificate is enough to get a refund, you will never hit the law because the failure to provide an accurate prediction warrants the full refund.
If people get really rowdy, refund anyways. Shoot even if it's late refund. I'd be super lenient with it, you will make plenty of money.
I think the laws are more liberal here (California).
I think if you offered a no questions asked moneyback guarantee for wrong predictions, then the only people paying would be people whose predictions were correct (assuming every person with a wrong prediction requested a refund). You would of course put a disclaimer (as psychic hotlines do) that it is for entertainment purposes only, etc.