Day Three of the RV in the Shop

Greetings maties! Gather round and listen to our tale of woe and unhappiness. Today is day 3 of having the RV in the shop. This place would not have been my first choice to repair an electrical disaster. I think they're OK for TV installations, cabinet work, flooring and the like, but not weird power stuff.
Exhibit one: There are 3 multiplexer boards in the panel. Two of them were fried on Tuesday. Wouldn't you think that it might have occurred to the techs to pull board number three and look at it? If two out of three are fried to a crisp, wouldn't you look at the third? Apparently not. They discovered that number 3 was toast this morning. Its replacement will be here tomorrow.
Exhibit two: Great whanging goo-gobs of electric current were required to fry the boards. Where does that volume of power come from? The alternator. The owner told us today that the only source for that much power is the alternator and they were in the process of removing it to send it out for rebuild or replacement. If they knew this, why did they not do this on day one?
So, we're unhappy. They may have it done tomorrow, but it's not likely that we'll be able to drive it away as the extended warranty people will want to come out and look at it first. That will not happen until Monday at the earliest.
This has been trying on so many fronts. One of the reasons we really resisted buying a Class A is because of exactly this type of situation. There are so many power management systems on board; there is shore power, generator, batteries, inverters, converters, 12V. 110V and etc. Jim and I are not engineeringly inclined people because we haven't needed to be. Until we're further down the learning curve, we have to rely on the repair people, and many of them do not deserve the trust placed in them. If this shop is able to positively identify the root cause of the problems then we can go forth happily. If not, then we're in the position of not really being able to trust the RV.
So, that's where we are as of Thursday night. The good news is that we have clean clothes and we got our bike helmets out so we can ride tomorrow.