Former Ins Salesman

The purpose of Insurance, in this instance (unlike Health ins), is to make you "whole". Its the very premise of why you purchased insurance.

Clearly they are playing hardball. For add-on items, above stock or the evaluated vehicle by your agent, you will need to show an effort to get coverage. If all items were on vehicle when agent insured vehicle, then they are covered unless you waived them. Its the agents responsibility to provide proper coverage, including physical inspection.

All insurance agencies are regulated by your State (in US). Start complaint process with State. Read your contract for arbitration or claim disputes. Document everything. Calls, contacts, everything.