Asking WebMD about a rash on your arm isn't and should never be considered a proper substitute to the advice of a licensed medical professional for a proper diagnosis and treatment regimen. 

Overturning a diagnosis will not happen, it does not work that way.

First, do a bit of diagnosis yourself.

It seems like if this would be possible, I'd have gotten a better diagnosis so far.I would have to hire some labor for the delivery and placement, removal of the old furnace as well.

One of my roommates did a bit of diagnosis on the problem which proved to be helpful when describing the issue to the HVAC Repair Dispatch.

First they came out and charged us the fee and did nothing about the clogged sink. 3 days later, there was still no diagnosis and a week later they told us it was not covered bc the clog was caused by grease (we think not!)

It should also include any diagnosis/estimates by contractors for repairs.

Who should I call for diagnosis?

The seller was a past client and found himself needing to move out of town to be around family due to a bad health diagnosis.

If she has a diagnosis of dementia or someone took you to court and it was clear she was not competent, all of your time would have been wasted anyway.