First things first: Evening at the Talk House is a production of The New Group, not Signature. They are simply renting one of Signature's spaces. So, the people you should be contacting are the customer service administrators for The New Group. Of course, they are under no obligation to accommodate you--that's why they tell you no refunds or exchanges when you buy your ticket. But if you contact them and politely request to be accommodated, they very well may. Good luck.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body