Under normal circumstances you could always take the bike back to their shop and have them fix it. In fact I believe they offer a free adjustment after the first couple of hundred miles. My chainline was a little off and mangled the chain on my new bike but they replaced and fixed it no charge. All shipped bikes are sent partially disassembled and require some tweaking, even new ones. If you pay a professional bike shop to assemble it they’ll get it right for you, otherwise you’ll have to do it yourself.
And if push comes to shove REI has a we’ll take anything back return policy, no questions asked. You always pay a little premium at REI but I’ve never had a problem with the service. Always top notch.