I too have been scammed as I got my latest Cell phone bill with a 34 dollar additional charge...due to textchallenge. They very subtlely got me into it and when I enquired with my service provider, I was told that they have no responsibility as they are billed and they pay "text challenge" and the service provider recover it from the cell phone user.
The lady in text challenge told me also to email to
info@textchallenge.com about my grievance and they would investigate and revert within three business days.
Personally, one has to make a strong complaint indicating how they got into it without even indicating the implications of an additional extra charge all through.
Well, laws support a commitment in the form of an agreement, but any agreement secured through tricks or manipulative tactics will I believe not get the support of law. Therefore have your story ready and be ready to back it up as far as possible.
Perhaps all those affected by this mischief need to get in touch and collectively form a case and I am sure we will establish who are the aggrieved ones..