Id go back to the insurance company again and speak to a supervisor. Many, including mine, will make sure you are happy with the repairs or send it out to another "approved" facility to make sure the insured is satisfied with the repairs.
If that doesn't work, you have some options. Pay by credit then dispute it, pay by check and cancel it (give them the check on a Friday or Saturday just before closing), or negotiate. Either way you should next take the rig to your insurance company's approved repair facility.
Paying then canceling the check or disputing the credit charge usually makes the issue a civil issue versus criminal when taking back your own property; depending on your state laws. (I'm not an attorney so you get what you pay for in advice)
Good luck