The estimated delivery date will be changing each day because you are looking at the current listing. The dates you are seeing are if you bought the item today. If you click on the listing in your purchase history, there should be a link at the top to go to the actual listing you bought, which should show your ETA. 

As for wanting to refund to sell to someone else, seriously, what would be the point? To gain an extra $3? They had a sale from you. Sellers like to make sales. They aren't going to hold off, or force a refund, so they can sell to someone else. That makes zero sense to me as a seller. That someone else may never come along.