When I do read it over, it seems what we're really doing is assuming the loan.Please, someone, explain what the difference is.  

Oh yea, they called me up SCREAMING that I was trying to rip them off, after I explained everything in GREAT detail, even went over the cya acknowledgments TWICE and they still said I never told them everything.

Should I send the check back and explain that I don't accept partial payments?

You may be dealing with some low level servicer employee who could care less as that isn't their job, so you need to explain if you can talk to someone, you also need to notify the Trustee as they will have to inform the lender but they have no duty to talk or deal with you.

Contact the LL and explain to her how it's making you sick.

@Martin SI think you would have better luck if you sat down over a cup of coffee with the agent so you can explain what you are looking for and let the agent know you are serious and not have the agent chasing deals where you will be making low ball offers and never close.

I explain the the property is available, but only by assignment.  

But this was after having a track record of 3-4 rental properties bought well below ARV and explaining that I would use these funds to purchase additional properties. 

I was thinking when I call them next (tomorrow) I could explain the concept of a lease option and see if they show any interest (at least it'd save them the realtor commission) but otherwise I think they'll be a follow-up.

I'd need to explain the investment.