Progressive RV Insurance Scam

I retired from a P & C Insurance Company. Every state regulates insurance rates and coverages in one of three ways. Some states stay out of it all together. Not many. Some states control what can be sold and set the rates that can be charged for that coverage for every policy sold in the state. "Defined Coverage" states. And some, like California, are "File and Use". Companies file their policy coverages and rates with the state, but the state doesn't dictate the coverages or what they charge. That information is in the body of the policy. We know you didn't read it, but relied on your agent, who also apparently didn't read it.
Replacement cost coverage is generally available as an upgrade, but the premium is also higher. Sounds like your agent let you down by not telling you about your coverages. I'd be looking for a different agent.