Yes, if they don't respond satisfactorily then do report them to the Better Business Bureau. It's very easy to do at their website:
http://www.bbb.org/
I filed a complaint with the bbb after a retailer repeatedly ignored my complaint after multiple attempts to resolve it with them. Boy, did the BBB complaint I filed ever get a response from them! They immediately contacted me and made it right, apologizing profusely, etc. It really does work, businesses don't want to get a bad reputation with the public, so sometimes they have to be prodded to do the right thing.