I'd say yes?

But I'll also throw out there that the missing bike isn't really their fault. Seems Salsa is notorious for not getting stuff made in time, or when other people get their bikes made, and for only having one model ready when they expected the entire next year's stock to be done. The shop may be trying to pacify you as best as they can (and cover for Salsa) when they really have no idea when they'll get it in.

Not saying you should keep the deposit on your bike and stick around waiting for a bike that won't show up. Definitely ok, at this point, to change your mind. They won't have any problem selling that bike once it ever shows up. And edit - yes, they should be able to do SOMETHING for you in the meantime, not just feign ignorance.

But as an analogy, you're dealing with a server covering for a disorganized kitchen, with no manager to step in and make things right.