Hey,
I feel you brother. I loathe insurance companies because of this kind of behavior. I am going through the exact same thing right now with my wife's Scion Xb. But I've been in this situation with different insurance cos atleast 3different times with squarebodies. A guy rearended us and I'm dealing with his insurance co this time. So far, they've worked with me and have been answering the phone. They've been farely unconcerned, and untimely though. But I feel the road might get bumpy soon. After three weeks of negotiating they finally told me this morning that it would be a total loss. But I feel like I'm gonna be arguing with them for another week or two about value.
There is some very good advice in this thread. I just wanted to reiterate. Keep your cool, and be reasonable. Don't go away, and you do have the right to what it is realistically worth. Certainly don't depend on their comparables. I usually do ok, after fighting for awhile. I wouldn't offer receipts unless they asked, personally, or all else failed, depending on what you've got they will probably claim, "wear and tear". It does suck that they are treating you the way they are though. Normally dealing with the other guys insurance is much more pleasant in my experience.
Also, since people are bringing it up, I wanted to offer a different point of view about insurance companies. I've dealt with many different insurance companies over the years (I've been in a bunch of wrecks, for some reason. Except for the Bronze Blazer (which really wasn't my fault) it's been years and years since I had an at fault accident). I know I'm long winded. I told you that to tell you this. I've come to the conclusion that (auto, atleast.) insurance is a scam
I usually pay for the least coverage that I can get. The absolute state required minimum. I typically just have liability coverage with a high deductable to get the lowest premium I can. I just don't understand paying a high premium when, if you do have an accident, all they're gonna do is try their best to break it off in you--and then raise your premium. Of the 10+ accidents(It's hard to keep count, maybe all the head trauma?) I've been in--only three where my fault (technically), and two of them where from my first years with my liscense. I'm confident in my driving ability and don't feel like I am likely to cause an accident. And if I do--that's why I drive vehicles that parts are plentiful and relatively cheap--I like to think that's in the spirit of hotrodding anyway. Chances are you can fix it for far cheaper than that what you've thrown away on a high premium insurance policy.
Of course there are exceptions. If you owe money on it, or you are an offensive driver, or there are a bunch of guys whose trucks and other toys and stuff do fall into categories where these collector car, antique, leasure vehicle, and agreed on value policies do make some sense (ie.--if you have $10,000 tied up in suspension). But not for me, not right now, not with my vehicles in the state that they are in.
For the two guys still reading. Thanks for letting me rant.