How do you handle a nightmare owner?

I just finished a three-day drop-in job for a cat owner, who wanted someone to visit their cat three times a day. I had a bad feeling about it as soon as I accepted it - for one thing, the location was very inconvenient for me (though that was my fault for not looking at the map closely enough) and one red flag should have been - why do you need someone to visit your cat three times a day? Seems excessive but hey, that's not for me to decide. Then she gave me a huge, very detailed extensive list of instructions. Ok great! Some of her instructions seemed a little excessive (wash his water bowl every time and then only fill it with the special filtered water, throw out the disposable plates that he eats off of, etc), but again, I chalked it up to her being a very involved owner. These all should have been red flags. I am a cat owner and I love my guy, but this seems crazy!

Anyway, she gets back after three days and then flips out at me on the Rover app, saying that his food area was a mess and there was water everywhere (there may have been a fleck or two of food on the ground and some drops of water, but he's a cat! That's what they do! It certainly was not a "disaster" as she claims). Then she accuses me of not feeding him at all (ok WHAT?) and then says I have no business sitting pets, that I'm a "liar" and that she's reporting me. I tried to respond as professionally as possible, then she claimed "I know you're lying and I have proof!" (Ok? What? Even if she had videotaped me in her house, she would know that I came 3x a day as instructed and refilled his food and water so... what is she talking about?)

Clearly, this woman is a bit unhinged, but I do expect a bad review in the coming days.

I called Rover support as now these messages are turning into harassment and wild accusations. The support staff member I spoke to agreed with me, saying that he could clearly see the photos I sent to her and that there was plenty of food and water in his bowls. He said they could ask her to stop messaging me, but that wouldn't stop her from sending me messages in a new thread. He also said they could not block her from contacting me.

Honestly, I'm a little scared, not so much from one bad review (as this kind of stuff happens) but the fact that she's lying and clearly a little crazy.

How should I handle this?