I would: 1- Turn off the ads; 2- call them early in the morning and tell them that that ads are offline now and you are working on your geo-targeting software; 3- tell them you'll call back when it is ready to go; 4- Work on your geo thing and call them back when you are ready. YPN guys are very understanding.
I would say thats too bad of YPN - they didn't gave such warning to all - just yanked the account. Well you are lucky to get such warning - better filter non-US traffic first.
This is so stupid. Why don't they just filter out all International clicks? This is why I hate YPN. They seem so behind the times in just about everything and can't seem to do the simplest things. How did they ever manage to survive this long I'll never know. No wonder Adsense is running rings around them when it comes to innovation. YPN are like dinosaurs, moving at a glacier's pace.