Thanks Ellen, it will be interesting to see what happens now then, as from what I've read, as they accepted the money and issued an email saying that the subscription was in place, that it could act like a contract and they may have to stand by it even though it was a mistake as people paid the money in good faith. I suppose it depends how many people were able to take advantage of the offer, whether they can afford to let it stand as a gesture of good will. I expect they will take legal advice before doing anything.
I wouldn't like to be the person who put out the offer!!