I'd withdraw it all. Store it at home, barricade myself in and wait for normality to resume. Yeah totally calling the alien's bluff on this one.

Once normality has resumed I'd do what I'd do if I won the lottery, pay off family mortages, give some money to family, give some money to friends, donate a load to charities that are important to me, treat myself to a few things and consider going back into education or persuing some potential hobbies.

Maybe I'll even buy the aliens a round of shots too.

"Ho boy you got 'em good with that threat, you should've seen their faces. Priceless!"