100% agree you need to know the terms of the contract.

What seems odd is that they took the booking, confirmed the booking and rates, but then are now seeking to modify the booking. Not a simple 'rate isnt available'...This may be a wrinkle ...again depending on the terms of the corp agreement,

Just because you have a contracted rate does not mean there is a complete separate agreement that defines every aspect of the transactions. Normal business practices and consumer laws may still apply. (Like acceptance of a booking may still be a binding contract...) Maybe.