Just tell them you decided you don't need them and hope for the best. Worst case scenario, if they won't refund your money, just list them for sale in the marketplace here. Maybe someone will pay $5-10 for them.
I think you're on the right track, somewhat.... and almost everyone loses money initially... but if you like the geo-domain route, I would recommend swapping out "alcohol" (liquor or beer would be better, I think) with other keywords, across various categories and locations. Also check the Google Adwords Keyword Tool to see if there's much competition for the keywords in question. You'll get there. At least you're registering .com's. A lot of people get caught up buying .net, .org, .info, .biz, etc, and that's typically not gonna make you money!