That's frustrating. But I'd bet that all the other parts were copy/paste with name change as well. Just coming from archives like ours or literotica, where the story text itself won't show on search engines, so you have to be familiar with the story. Given that your piece was from a completely different fandom, I'd bet that the other bits (if stolen) came from non-Marvel fandoms as well.
I hope the site works with you on getting it down quickly, if you're able to get in touch with them.