I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client privilege.
I cannot picture the accident in my mind. But if the type of accident you had is considered no fault on your end, then you should have his insurance company pay for everything. Now, if indeed the insurance company has the legal duty to pay out under these circumstances, then what they have been doing is considered bad faith.
May I suggest you begin by reading the insurance/auto insurance/insurance bad faith sections at the freeadvice.com homepage. After that point, may I suggest speaking with them again and also letting them know of their duties and telling them: if they don't comply, you will have no other choice but to contact the Insurance Commissioner and your county's better business bureau and possibly an attorney.
Hope this helps.