Am I getting pranked?

Here's my situation. My car was struck from behind while it was parked, but the driver who struck me was swerving to avoid another driver. Driver A is insured by Allstate, Driver B is insured by Progressive.

This accident occurred in September. At the time I didn't have collision insurance, so I'm relying on the liability insurance of the other drivers. After a very long deliberation, Progressive told me they would accept 20% liability, and Allstate told me they would accept 60%. That obviously doesn't add up. The adjuster from Allstate told me in December that they had entered arbitration with Progressive to decide on the final liability.

In January, I called to check in with Progressive. The adjuster there told me on a voice mail that no such arbitration was being held, and they were liable for 20%, end of story. I have called both adjusters 4 times each since then, leaving voicemails twice, and gotten no answer or call back.

What is going on, and what can I do? It seems like they're ignoring me, and I'm no closer to getting my car repaired than I was four months ago.