How do you sue a Chamber of Commerce ?

I applied and was accepted to be a concession vendor selling Lemonades and soft pretzels for an event held by a Chamber of Commerce. ( In NY State ) I was sent an acceptance invoice and I paid a $500 Vendor fee to the chamber , $75 for county health permit and Purchased $2600 in supplies for the event . 5 Days before the event my concession was cancelled by the chamber stating they do not accept drink vendors. I had cancelled other events to attend this event due to the Size of it 50k people attending over 2 days . I sent the chamber an invoice for monies lost / damages . Vendor Fee $500, Doh Permit $75, Supplies $2600, Staffing $2000 and Lost revenue $19,600. Total $24,775. Lots more details but this is the jist of it .