Signed contract with hotel under false pretenses, do we have a legal leg to stand on?

Hey legaladvice. Long time reader, first time poster. I have a situation at work I’d like your read on to see if we have a case.

I am the new Event Director for a small non-profit in New York City. This non-profit hosts an event in December for 150-200 guests. My predecessor signed a contract with a major hotel for event space, but when I went to tour the space shortly after being hired it was clear the space was way, way too small for our needs. Luckily I have access to the last director’s email, so I was able to clearly see what happened. Our sales manager at the hotel made a mistake on the initial quote so by the time she sent a new quote, the original space the last director had viewed was now unavailable. The sales manager recommended a different space for that event and confirmed this space would work for our group size. After some back and forth, the old director signed the contract.

So now I’m fighting with the hotel. They’ve admitted they are at fault, but while there is appropriately sized space available at the hotel, they are now trying to extort us for $10,000 more in venue fee and $5,000 more in food and beverage minimum. They claim this is because of “union rules” which seems like a load of bs as my understanding of union rules is it’s based on attendee count, not the size of the room. Our attendee count and event specifications have not changed once throughout this process.

So my question to you all, do we have a legal leg to stand on? This isn’t a breach of contract as the contract is correct, it was just signed under false pretenses. We are a small non-profit running on razor thin margins, so an unaccounted $15,000 is a lot of money for us. And it hurts even more as we did nothing wrong (perhaps other than the old director not doing her full due diligence to see the updated space before signing the contract). I’d love all your thoughts, thank you for the advice.

Location: New York