With many hotels, if you call them directly, and either select Reservations off of the auto-attendant, or speak to the front desk and ask about a future reservation, you get immediately transferred to central reservations. You kinda have to be delicate in how you word the situation to avoid that happening. Once you get the front desk, you might say something like "I have an issue with a future reservation that central reservations can't handle. I can I speak with someone in revenue management?"