You bought NIB from a distributor for a reason, you should be covered here. Call and respectfully insist on exchange for a new game with intact glass. If you decide to accept a discount, make sure it's big enough to account for the long-term hassle. Never had to deal with it myself, but there are plenty of threads on Pinside where you can read about the joys of cleaning playfield glass out of a game, and how you can never seem to get it all.