Either the travel agency or the hotel made an error.

I do not see any basis for an insurance claim, but let us know what policy language might cover this circumstance.

I do not see any basis for a credit card dispute against the hotel, because you authorized payment.

If you file a credit card dispute against the agency, the best outcome will be a refund of the original payment because the room night could not be used. The card company is not going to help you recover consequential damages.

I think your first course is to work with the travel agency directly. I would contact them only on a weekday during normal business hours in their primary location. They may not take any responsibility for the higher cost of the room, claiming that you should have contacted them when you arrived at the hotel, rather than agreeing to pay the higher rate. (I am not saying that I agree with this, only that you should think about how you will counter this position.)