I'm still not willing to let the housekeeper off the hook for not understanding the note. I said it before, if she couldn't read it then she should have found someone to read it to her. Many times I leave notes asking to change the sheets, for more soap, shampoo, coffee, towels, etc when I leave my tip. I expect those notes to be read and the items to be delivered to my room. I would expect the same without the tip as well. Even someone with a rudimentary understanding of English should know the English words for those items commonly used in their jobs: "sheets", "towels", "coffee", "soap", "rug", "TV", "sink", "tub", etc so she should have had a half a clue that "towel animal" had something to do with towels. If she was a Spanish speaker the word "animal" is the same in both languages. My guess is that she simply did not want to make the effort to try to understand the note or she didn't care if the OP received what the asked for.
FTR, I am usually on the side of the housekeepers. They do what I consider a hard job and I don't mind tipping them for their services. But I can't stand it when someone gets blown off like the OP. If you can't make the towel animal ... fine. But don't take the tip for a service you are unwilling or unable to preform.