[Was I defrauded by "graphic designer"?]

I saw a profile of a graphic designer with skills in Adobe illustrator and he had a gig for designing YouTube banners. He had gigs priced from $5-$20 but when I chatted with him he said due to not getting a lot of work and because Fiverr taxes his pay he is charging me $30. I eventually got him to charge me $20 but he wanted a tip at the end.

He gave me a banner and I closed the gig. Later I uploaded it and showed friends and a friend said the banner looks familiar and dropped it in Google images and gave me the link. Over 75% is a free commonly used Japan pic and he did slap on a small rectangle with me my channel name and a black vector of a couple on the right side. Is this allowed? I was under the impression he was actually going to draw something as all past artists did for me, especially because no charged me the max $20 and I gave a $12.50 tip thinking it was original in some way. I don't want a banner that's too much just a public domain photo with a minority of change of just my name and a public domain couple vector slapped on. At least be clear at a certain price it is not illustration but just public domain photos and minimal changes (no actual illustration). I tried to be fair and ask the artist for 50% refund and he blocked me and told me he is happy if I take it to Fiverr customer service. Its just doesn't seem fair to past artists who really did illustrate. In a way I feel defrauded. What are your thoughts? Thanks.