I'm sorry but where did the 748mbtc come from? how much did you win from the "free play"(I'm asking because I am curious whether the rollover was based on the amount of money you won from free play)? also, I don't think you need to win 748mbtc, you just need to wager that amount.
anyway, I hate bonuses that automatically apply on deposit. all bonuses should be opt-in and should not be automatically applied.