There is no prize, just a scammer using a lying SMS as bait in order to collect your money and details, then put a virus on your phone to copy your contact list. When he gets what he wants he blocks your calls, and sells your identity to the highest bidder, who cleans out your bank account.

Do not reply to the SMS, just delete it. If you did reply, contact your bank and phone company right away.

It is called the Nigerian 419 scam, look up the Wikipedia article on Google for more information.