I've had a minor dead spots here and there on past basses... even very expensive ones. Sadly in my case, the only real fix was getting a different bass that seemed to have none! Now, I didn't sell those basses because of apparent dead spots alone of course. In fact, I've always learned accept the odd dead spot as part of the individual bass and its character... being made of naturally varying woods, metals, heavy components etc... I find that dead spots can arise naturally in varying degrees in all sorts of basses for various reasons. It reminds me of chasing wolf notes on my old upright... very obscure, yet solely related to the resonance of the bass and the sum of its parts.
If the decay of the note is absurdly short and crude (which I have heard shocking examples of here on TB!) and clearly a defect of sorts, I would definitely pursue a replacement instrument from the dealer as previously recommended. Nobody should be burdened with this type of disatisfaction this day in age when spending proper $ on a proper bass! However, If the dead spot on the subtle side of things... I would suggest hanging out with the bass for a while as you might find other great qualities in it despite the dead spot... which may also lessen over time given that this is a brand new instrument etc.
All things to consider IMHO and I wish you luck!
EDIT: Ive also experienced what I felt were "dead spots" on basses at different times in different playing environments on different places on the neck. I attribute this to the added feedback/resonance from being amplified etc. Therefore, I feel its critical to make all of your assessments while testing the bass acoustically!