My sympathies to all like experiences, most of us have either been there or will be.
One method that seems to get results for me:
1. Before you make any contact with them grab steno pad or small notepad.
2. In person or on phone, write the name of person that is responding. If on the phone, ask them to spell it even if it's a "Bill" or a "Mary."
3. It will soon become obvious to them that you are taking notes on what they tell you.
4. If not happy with their responses (please be reasonable here, they're not getting their parts from Amazon prime):
5. ESCALATE!!! Take your notes to the sevice manager once. If not somewhat pleased, they have people in charge of them. Frequently I have dealt with owners.
I have found Thor very helpful on my new Palazzo, however they can only "support" the dealer.