There are only two reasons I remember that you get the "call HTC". One is you got band, the other is your credit card/bill payment has an issue. Did you cancel your credit card and forget to inform HTC? Did you forget to send in the payment to HTC?
I don't think it can be fixed over the weekend so you'll have to wait until Monday. If you want, or NEED to play this weekend you can open a new account with a good credit card and get it straitened out Monday with a phone call.