^^^^This. Get what you want. The replacement is not to your liking; you should arrange a return. As others have mentioned, see if you can have the first one repaired under warranty and shipped back to you (possibly at your expense, if that makes it easier to negotiate). You've learned a valuable lesson.No reason to keep one that you don't like.
Why are you assuming everyone is hostile toward the seller? If this is a commercial seller engaging in online transactions, that comes with certain responsibilities and risks. One of those responsibilities is the satisfaction of your customers. However, I do agree that the seller is under no obligation to ship multiple basses to the customer until they find one that's acceptable. At a minimum, the seller should agree to take back the second bass and end the transaction so that the customer is not stuck with a bass they don't want. Hopefully, the seller and customer can negotiate a repair and re-ship of the first bass so that both parties end up happy. That should be the goal.The seller already picked up two extra shipping costs on a $675 bass. They already burned their profits on these extra shipping charges. Now you think the seller should pick up two more shipping charges in order to exchange it for the first bass again?!?!?!
Wow, really I am surprised at how none of you have any sympathy for this seller. Sorry, but the OP has been playing bass for 10 months. He knows nothing about setups, and he knows nothing about his warranty options. He doesn't even realize that these basses all have identical frets. He probably doesn't realize that different playing attacks require different actions for ideal playability.
The seller accommodated this guy to a reasonable level. Asking him to do more is just abusive to the seller. No one in America has any respect for business anymore. There is this pervasive attitude of "if a businessman has more than me, I have the right to abuse him".
It's too bad the seller (who has much more experience than the buyer in this case) didn't offer a repair solution. Perhaps if the buyer had more experience (and certainly does now), the outcome of this would have been different. I have no doubt that the seller felt that shipping another bass would resolve the problem, but alas, it did not.
And that is one of the risks of being in business (online or brick & mortar); there's no guarantee that every deal you do is going to work out. Sometimes you take a hit. It's not abusive for a customer to expect to be happy with their purchase; certainly not in this instance.