Stuck with a car rental bill I cannot afford to pay

I was in an accident late last September where the other driver made a left turn and hit me on the driver door/left front fender area; no injury involved (thank goodness). My car was inoperable and was towed to an auto collision shop. After about a week, the other driver's insurance company accepted liability and presented an estimate to the shop. After about another week or so, the shop informed me that there are "supplemental" damages that need to be seen and approved by the insurance company before they can start the repairs. After another week or so, I was told that the adjuster still haven't sent somebody to inspect and present an estimate for the "supplemental" damages. From here on, I was preoccupied with trying to work for a living. Around mid-November (about a month and a half after the accident), I dropped by the shop to check the status of the repair of my car. The shop then told me that the insurance company still hasn't taken care of the "supplemental" and that repairs cannot be initiated until it is approved. I then brought this to the attention of the adjuster who in turn blamed the repair shop for not calling in the "supplemental" or something like that. They are blaming each other for the delay but in the meantime, my car is still sitting on the lot. Anyway, they finally got the ball rolling and parts were ordered albeit further delayed due to the Thanksgiving holiday week/weekend. My car should be done by next week (hopefully by Dec. 14). The total estimate of the damage is around $8000.

Since the day of the accident, I've been on a rented car so I can continue to go to work and go about my daily business. If you're from Southern California, you would understand the importance of a car to survive here. I associated the insurance claim number with the car rental contract . After, leaving several voice mails to the adjuster (no live person ever answers the phone) about my car rental bill for weeks, I finally got a call from an assistant who told me that they're mailing me a check for $600 for the car rental. I told her that that amount is not enough because at that point in time, the bill was already around $2000 (i.e. $30/day rental plus $10/day loss damage waiver for a total of $40/day and possibly plus applicable sales taxes and approaching the second month of the rental). She then suggested that I should mail back the check which I did. Since then, they haven't returned my calls/voice mails. Meanwhile, the car rental company has been hounding me regarding the bill because according to them, the insurance company is not accepting the claim (or to that effect) and therefore cannot set up/establish "direct billing" with them.

Just in case you're wondering why I have to haggle with the other driver's insurance company directly instead of through my insurance company and why I had to opt for the $10/day loss damage waiver for the rental car -- I only have third party liability insurance when the accident happened. I know, I know...but I had to cut down on expenses and had to drop the comprehensive coverage after I had paid off my car last year. I had to take that chance because I know I'm a safe driver and have never been in any collision wherein I was at fault. It's either that or drop my health insurance coverage. I'm one of the many who have been adversely affected by this economy with maxed out credit cards (mostly closed accounts and just paying them off) and currently only having a low-paying job and working long hours to pay them off and survive at the same time. To add insult to injury, this guy broadsides me as if my life is not complicated enough. I couldn't even begin to think where I'd get the money to pay for the car rental bill. I'm also concerned because though I'm heavily in debt, my credit rating is very good (no defaults). This is really stressing me out and is affecting me health wise.

So, what do you think is going on here? What are my options or recourse as far as getting the insurance company or the insured/policy holder to pay for the car rental bill incurred for the loss of use of my car as a direct result of the collision? Should I wait until the repair of my car is done and conclude my car rental and present the final bill to them? The bill would probably be around $3000 by the time my car is out of the shop (about 2-1/2 months rental at $40/day plus applicable sales taxes). What then if they still don't capitulate? I'm aware I can file a complaint against the other driver/policy holder but can I also name his insurance company as a defendant within the same complaint for handling my claim in "bad faith"? If so, would the Small Claims Court be the proper venue for this type of case? It seems to be my only option since I obviously cannot afford a lawyer. I'm also thinking of filing a complaint with CDI (California Department of Insurance) but I'm not sure about the extent of their scope.

I apologize for the long-winded story, folks. I just want to make sure that I present all the details.

Thanks you for your patience and any help/advice is greatly appreciated.