[Tony Van Helden]

It is difficult to see how you may get your coach out of your predicament short of an understanding between you and the shop owner to have it taken out his hands and to a competent repair facility and possible legal action.  Unfortunately, they have clearly demonstrated an inability to repair your coach.  He must surely be bonded for such situations that may give you some cover.  The owner needs to clearly know what legal action you are willing to take to get him to let go and both of you walk free and clear off a bad situation.