Starluck IGMPAY bonus -- cashing out?

[jrz1972]

I recently did the IGMPAY bonus at Starluck, which carries a $1800 wagering requirement. I am 99% sure I played through that, but I decided to email support anyway just to make sure. Unfortunately, the letter I got back from support didn't answer my question (go figure).

I'm going to email them again, and I can't cash out for a few days anyway because the e-check has to clear before it would process. But let's say I never get a satisfactory response from support, and let's say I miscalculated the amount I wagered and I'm actually a few $ short of the WR. What would happen if I tried to cash out? Would the software just automatically block the cashout attempt, would I get a pop-up warning, or would it automatically take back my bonus?

(This being PartyGaming, the T&C are silent on this issue as far as I can tell).