Call US Soccer. I'm sure you can get them at Will Call. They do have a number IIRC for just such an emergency. Go to their website. As much as I criticize them, I don't think they want to keep you out of the match. I see you weren't charged. Heck, just buy the cheapest tickets and sneak on in to the supporters section if the tickets are for another area. It's not like we're going to narc on you. Don't worry about it!