Wow. I sympathize. You have the right to vent. I remember when I lost a seal for an injector (spewed fuel everywhere) on Good Friday north of Chattanooga and had my camper towed to the nearest Dodge dealership. I was worried we would have to rent a car and drive home (only 135 miles) or camp in the dealership parking lot! We had to take the TC off the truck using the tow truck to pull my truck out from under it so they could get the truck in the shop to look it over.
Instead they fortunately immediately diagnosed the problem, found the part and had me on the road in about 3-4 hours, just as they were scheduled to close. I was very fortunate.
It seems there should be some recourse to motivate these guys to at least give you a diagnosis, proposed schedule or a reason why they have not done so. If they have failed to do this, I would become increasingly suspicious and cynical about them with each passing hour regarding any provided diagnostic explanation.