excess on insurance

[jacktayl]

Another driver hit my car and it was written off. He admitted liability. My insurance company have offered me much less than the market value and also informed me that the excess will also be taken off the final offer. This has left me next to no money to buy another car. I was told when I informed the insurance company in the beginning that I would not lose my excess as the other driver was with the same insurance company as myself. can I refuse this offer