@Andrew2588 Unfortunately, Airbnb usually refuses to remove reviews unless you can point out to them what specifically violates their review policies.
Lies apparently don't because Airbnb takes the attitude that "it's a reflection of the user's experience". Guests who have been called out for rule breaking during a stay will often leave bad reviews that consist of nothing but fabrication. Airbnb will refuse to remove them, it doesn't even matter if the host has 100 5* reviews and the guest is a total newbie.
Normally they wouldn't know which party was lying-it's just one person's word against the other's.
That you have photos, however, may help and you should never take one CS rep's decision as the final word. So if you really want to spend the time, you can pursue it, try again.
In the meantime, leave a review response. It will appear on your review page, not the host's, and be read by future hosts. So all you need to say is something like,
"I don't know who this host was reviewing, but it wasn't me. There were numerous issues during this stay regarding the non-functioning toilet, the host's intrusiveness and lack of respect, so perhaps this was a preemptive strike in presumption that he would receive a bad review. He had tried to pressure me to leave a good review and I obviously would not promise to do so. I have photos of how I left the place (clean and tidy), taken before check-out because I didn't trust this guy, and I was correct. The review is a complete fabrication.
Please refer to my other 39 reviews for an accurate picture of the kind of guest I am."
With a response like that (or likely even without a response), the review will not trash your ability to be accepted by other hosts. Hosts aren't so naive that we would believe a review like that when you have 39 positive reviews. We know there are sleazy hosts out there and we'd love to see them booted off the platform.
I did look at this host's review page and he has many great reviews. It seems the toilet issue started this stay off on the wrong foot and just went downhill from there.