read it a few times but not sure you are doing the math correctly.

If you lose the $3000 bet you are 3K in the hole (right?)
They now give $3000 in free play money.
You would have to win all $3000 to break even on the 3K you lost on the first bet.
If you break up the Free Play Money into several even bets and hit 50% of them you only have $1500 back in your account.
The money you used for the free play bets do not go into your real account - that money goes away win or lose