Yes. it's a little known fact since the tickets read no refunds or exchanges, but if the seats are available, most theatre box offices will exchange the tickets.
Also, if the star you came to see in the show is NOT performing, then you are entitled to a refund. To qualify as being the "star," his/her name has to be on the marquis of the theatre above the title.
For example: Jeremy Piven was contracted to star in
Speed the Plow for several weeks. He was in it for a handful of performances, got incredibly lousy reviews. He "suddenly" developed mercury poisoning

and left the show completely, without even a warning to the producers. But was seen 2 days later out in public, in L.A.
The theatre is refunding all the following weeks of tickets that he was scheduled to be in, IF people want to cancel seeing the show. Piven was the star headliner (on the marquis) which brought people in to that show who wouldn't have seen it otherwise. And if he's not there, then yes, people are entitled to a refund. (The producers are now in a lawsuit against Actors' Equity and Jeremy Piven.)
However, William H. Macy, who is a longtime friend of the playwright, David Mamet, and has acted in Mamet plays to such an extent he can do his plays in his sleep, has now replaced Piven. It is probably a much better performance than Piven's.