I have to agree that $30 is a bunch to pay for a screw...that shouldn't fall out in the first place. I'm surprised. I had two Dua's at this point, and both were excellent. I have NOT used their Customer Service (no need), so cannot speak to that. Send him another email, Check the screw size; perhaps you can match it at Grainger Industrial Supply. Link:
http://www.grainger.com/Grainger/wwg/start.shtml?gclid=CPjt3c6Vs7kCFY3m7Aodm0MAEQ&cm_mmc=PPC:%20Google%20Main%201-_-Brand>Brand-_-Grainger>General>Exact-_-Grainger&ef_id=Uifm0wAAAUIRtEmM:20130905020507:s
Too bad. Sorry for your problem.
Sonnydaze