You have a status card from CO? I know it doesn't say Star Gold until you get a new one from CO but you could flash that if it's the appropriate CO level that nets you *G. If you get hassle (always possible depending on a bad apple agent) you could pay the fees and then request a refund after the fact.

That's not the best solution but US has been pretty good about customer service responses in such screw-ups. I've had refunds issued for fees incorrectly collected at the check-in desk. Was easier to pay and get a refund rather than argue with a ticket agent not likely to budge and/or possibly at the mercy of a computer that won't let them proceed without a fee.