I know this kind of buyer a little too well. They are the kind who often have no idea how much a service should cost. This being the case, they project a cost which they feel is appropriate. I have had similar responses after spending 10+ hours on orders where the buyer has ordered a non-conventional service.
I occasionally get video orders where a buyer sends a power point presentation which they have meticulously made into a video storyboard. They then expect me to be able to wave a magic wand and make the existing material turn into an animated video. - Not realizing that I have to recreate every scene in completely different software and render it.
Buyers like this can’t be avoided, reasoned with, or ever fully satisfied. All you can do is let this experience go and be thankful that your other reviews more than balance out this one. To help this happen, maybe think about reviewing your buyer with:
“I am very sorry but like with all my clients, you could have let me know if you weren’t 100% happy with your order. You instead told me that you were satisfied. Maybe next time you order on Fiverr, think about contacting a service vendor prior to ordering, in order to discuss your project in more detail.”