I have a 2015 DRV that was in the shop eight of the first 13 months I owned it.
If you financed the RV you might get some help from your lender.
Getting a lawyer probably won't help. You probably signed the same type of contract I did that states you can't sue them you must go to arbutration instead.
At my age I have probably bought my last RV but I feel bad for the folks that buy this junk and just bang their head against the wall trying to get things fixed. maybe getting the lenders involved will help. If they get enough complaints maybe they will quit financing them.(probably not)
These folks have had so much practice dodging the responsibility of the issues it is almost impossible to pin them down on anything and all the while you are dealing with them your rig is out of service.
Good luck. Try to stay after them until they have made it right. Will be a frustrating journey.
Doug