[Clients] Do I just block this client?
So, I had a "failed" commission. We found each other online. The piece was a fully rendered nsfw piece. I was desperate for rent money, so I accepted $35. I kept them updated on the sketch and rendering, though I was a bit slow. Finally, when I submitted the final piece, they asked if it was a WIP and sent in their references again (which I had followed). Throughout the comm they continuously talked to me as a friend and even asked to stream with them? I shook it off mostly, just wanting to finish the art. Anyways, when I went to edit the piece to be more "accurate", I accidentally deleted a layer that contained the arms and my art program would not let me get it back. I broke it to them that I'm sorry, but this is the finished piece and I cannot edit it. Which, felt reasonable as the price was already low, I had went off a reference they provided, and it was nsfw. They had said something along the lines of "that's okay! It looks good. I wouldn't mind if you ever want to redo it." I kind of ignored that because they then switched to another topic. Since I finished the comm, I felt no obligation to redo a large majority of the piece that would take me another 5 hours.
Today they messaged me with a "checking in" and I realized, very horrified, that they're expecting me to continue to commission. As I said before, this person was a bit strange during the comm and it didn't help I was working for like $2 an hour (it took roughly 18 hours). Should I just block this client? Is it unprofessional?
Edit: Can't respond to the comment saw it in my notifs but won't appear. I gave them a finished piece WITH ARMS don't worry! It was completely rendered and on par with the rest of my work (though, I honestly didn't like working on it, but I pushed through). The arms got deleted post-finished comm when I decided to redo some of it for them. I did not tell them I was going to edit the piece, I just decided to. Therefore, they had no expectation affirmed by me that there was more to the art. Then, I told them honestly that what I sent was the final piece, as I had sent it in finished and had no way to edit it without putting in way more hours that weren't justified.