A reputable resort/campground will always offer a refund if not the entire cost at least partial compensation.
There is allot of rhetoric can be said for the park that knows you will return within minutes of heading out to your new site. Return for a refund they are depending on you not getting.
I suggest you always pay with a credit card that will stand up for your rites. It will allow you to contest the payment. Just the fact that you where allowed to pay with a credit card of a specific type, states that they have to honor the contract with that company before they will receive their funds.
I agree there are times of special interest like holidays or special events that may demand special consideration or heightened greed on the occasional hostelries part.
I do not do business with people that think you should jump through hoops to give them money.
You do not owe them or any one else a living. I consider the act of denying a refund blatant greed. JMHO
Not returning a deposit for at least one day is always acceptable. Deposits are another story altogether.