You didn't indicate how large the change fee is. While I agree there should not be a change fee, if it's a small amount I would accept it and move on with life. To be fair, they probably aren't obligated to offer anything based on the contract so you might consider it a blessing.

At Coconut Breeze Villas, we are grateful for everyone who is rebooking instead of canceling, not charging any fees, and honoring the 2019/20 season rates next year. Also, we don't require full payment in advance so our guests are only "loaning" us half their rental cost.