I had this problem once before and just gave up.
I just received 4 nice banana plants from Sandy, as advertised in her listing at
[Sale] Bananas and other plants 4 sale many varieties to choose from - Bananas.org. As requested, I did not click the "commit to buy" button as that would end her ad. When I try to leave feedback for her using the above URL, I get a message "Deal URL invalid!". How can I leave feedback???