Camping World Ruined my new brakes on my rv Houghton Lake Michigan

I had bought a 2014 Keystone Cougar Lite fifth-wheel and was getting some insurance work done on the side for hitting a post.(Aug,2014)One of the serviceman(dark hair,glasses,in his forthy's) said he also checked on the wheel bearings and they needed grease on the right side,so he added some.Now,The fifth-wheel only had 1,500 miles on it.I then traveled an additional 2,000 miles,and was in Georgia to get my wheel bearings and brakes checked(this should be done every 3,500 miles.This was at Camping World in Georgia around April,2015.They called me and said the brakes on the drivers side were fine,but the brakes on the passenger side were covered with grease and would need to be replaced.They said it looked like someone added grease with a grease gun which blew the seals.This cost me $300 dollars because of his mistake.They called up there and talked to the serviceman who said he checked the wheel bearings, but didn't recall adding grease to them.I had sent a letter through there email to the company back in May but still no response.