@ the OP,
Devils advocate briefly here, don't flame me (all of this sounds shady to me on the dealer's part anyway) ...
So the Oil Code reported on your W/O says that the fault was related to an Incorrect Oil Viscosity fault or something like that. Ok. (do you know what oil weight was used by your guy?)
They indicate that they couldn't determine what oil was in it and wanted to replace the oil vs considering an easily warrantable item like the oil pressure sensor (which may likely require and oil change in conjuction, which would then be covered by warranty). It sounds like the assumption was against the customer as the cause from the get go.
The brake issue. I can understand some slight brake noise may need caliper grease where the pad contacts the caliper (that's not unusual to say) but if the caliper actually locked up, that would be a warranty item, including the associated discs, pads, etc.
What kind of "brake service" did they want to perform that you refused and they claimed was justification for not covering this all under warranty? Did they say the pads were shot and needed replaced but that you refused that work and it caused the failure? Did you look at the pads yourself?
And why are you being charged diagnostic fee's for a vehicle under a warranty at all?
My guy uses 5w20, same oil they replaced it with.
I also told the dealer that if they're claiming my oil is "bad" they should take some it if and send it in for lab testing. Obviously this is an extreme suggestion, but if they're alleging my oil is bad the burden of proof rests with them. If the lab test came back showing it was indeed bad, I would eat the costs of the testing, but at least i can go back to my guy and have it out with him. Naturally they said they offer no such service, to prevent this from happening in the future I should just get my oil changes done with them. Trouble is their synthetic oil change is $170 with tax.
When callipers seized they only offered to do a brake service which i believe is $180 ($90 per axle). I personally don't believe brakes callipers should be seizing at 20k and if they do it shouldn't be an out of pocket expense to a customer. I drove the thing a few blocks elsewhere to free the calipers and that's where we discovered the pads and rotors were pooched from over-heating, rotors were discoloured etc etc.
The pads and rotors didn't fail because I refused the work and kept driving on them. They were already failed at the point. The third party I took it to to verify the brakes was just kilometre or two away from Dewildt Chrysler.
Why am I charged a diagnostic fee for fully warrantied vehicle? Great question! At least I know I'm not crazy.