Trying to close down scammers is like a game of Wack-A-Mole ... you hit one and 2 more pop up. Just use the old rule "if it seems too good to be true then walk away".
Think for a second ... why would a large company like Intuit possibly use Groupon or any other discount site to sell their program at all when they have an official site of their own.
This link Where can I obtain authentic TurboTax software? has a list of authorized TurboTax resellers.