Victoria Marine Damaged my boat hull Victoria, Texas

Let Victoria Marine work on boat engine for overheating problem WO # 12797 from 12/10/2009 - 01/06/2010 Got boat out of shop and was waxing it while waiting for weather to clear up. Nice day I took the boat out to the lake and ran it. The throttle was getting stuck, would not engage in reverse, steering was hard and it overheated took it back to Victoria Marine. WO #12812 01/12/2010 - 01/18/2010 To fix the throttle,steering, and the reverse(none those were a problem prior to first visit). Picked up on 01/19/2010 and discussed the overheating problem with Al (service manager)and picked the boat up. After arriving home noticed damage to the boat hull (scratches and gashes that was not there before I took it to Victoria Marine because I waxed the boat previous to taking it in. Called and spoke with Al he said to bring it back and let him take a look at it. Went back to Victoria Marine and met with Al he claimed that they did not do it. Al got Bob(owner) so he could look at it. Bob looked at it and said he was though looking at it they did not do it. Spoke with Charlie (mechanic) and he said that if he would have done it he would have told me and that they were old and it looks like it was rubbing up against something in the water. One of them made a comment it is not like we ran it over one of the cement blocks.