I received a free bet from Whale yesterday and played it very successfully. I just did not understand how it was calculated, because my odds were 2.00, but the winnings came out to exactly fifty dollars, the same as the face value of the free bet. Still, I was happy. However later I lost that money. I decided to buy free spins in a slot game, but they turned out to be completely unsuccessful. Still, thanks to Whale casino for the free bet.
This confused me at first, but it becomes clear once you understand the background.
If you win, you receive the net winnings (excluding the original free bet stake). In your case, with odds of 2.00 and a free bet of $50: Possible payout: $50 stake × 2.00 = $100
Credit of winnings: $100 $50 stake = $50 winnings
This is indeed standard practice for most free bet offers (giveaways, games here on the forum, ...) in order to prevent direct payouts of the stake. Only your winnings become real credit that you can (re-)use (or withdraw).