Bet365 rules on using account in the US

Okay, I'm from Asia and my account is based in my home country. I am visiting the US on vacation right now but should return within 3 weeks and I made bets that won while I'm here. I tried to make a withdrawal but Bet365 detected the US IP I'm currently on and suspended my account until I get back to my home country. 

You can guarantee if you had lost, you would have heard nothing about it. They should have refused your bet in the first place if they were really worried about accepting bets placed in the US.
In the same vein, all online books demand proof of identification AFTER you have made an initial deposit! If they were really worried about underage gambling and security issues, surely they would ask for that I.D. before the prospective customer makes a deposit.
Of course, as in your situation, once they have your money, they've got you trapped...you either do as they demand or they keep YOUR money.   

They will pay you for your wins but don't want anything done until you leave the states. They are just trying to avoid US Govt hassle.