We have State Farm but I've never made a claim with them. If your policy doesn't say ANYTHING about a surcharge and they insured your home, then do NOT let them get away with this! I worked for the Oregon Insurance Commissioner................contact the one in your state. Wait until the Ins. Co. gives you something in writing saying there's a surcharge. You would probably have to send in a copy of your policy and the paperwork saying you have to pay the surcharge. It's not right --- and it may be a "bad agent". The ins. companies don't like hearing from the commissioners.
Good luck!