Then, of course, you get the other end of the spectrum, and players receiving the wrong prizes. I have heard stories of players winning vacations on game shows and getting a fleabag room or having lots of bad incidents befall them, or receiving broken and/or damaged prizes in the mail. But the strangest was in a story about game show winners in the Inquirer (so take it with several salt mines) that said that a contestant was once paid out his winnings in cold cuts because the production company ran out of money.
At least they got the prizes - there was a mid-1990s syndicated game show called
Sports Snapshot that had players compete for sports memorabilia, and viewers could call in to purchase some as well; it turned out that quite a few contestants never got their prizes.
As for "prizes not exactly as announced," how about the "$75,000 treasury bond" which turned out to be the total amount of the payments over 30(?) years plus the par value, which was about half that? (It's sort of like giving somebody $25,000 and saying that they won $50,000 if they put it in the bank and collected interest. Of course, nowadays it could take quite a long time to double your money in a bank account...)