If you haven't called the slide manufacturer yet, it might be worth a phone call to them. My guess it's made by Lippert. Their website is
www.lci1.com and they can be reached at 866-524-7821.
Have you tried taking it in to another nearby RV repair facility other than CW? One that can get you in sooner, have the issue looked at, and repaired in time so you can still go on your vacation?