Rover help center doesn't help sitters?

Sorry this is going to be really long, but I need advice! I recently had a bad experience with a new client. I had to cancel our 3 night stay after the first 24 hours due to car trouble. My car was having an acceleration issue so I took it to the dealership and they said rodents had chewed up my computer wiring (never knew that was a thing)! They said it could take a few days to repair, if at all, so I notified the owner that we should probably cancel the booking because I didn't want to end up becoming unreliable and I'd rather be safe than sorry. She requested her dogs not be left alone for more than 4 hours and I couldn't promise that in that moment anymore. She had informed me prior to the stay that if anything came up her sister lives across the street and she can take over for me. The sister was contacted and went over no problem. For some unknown reason the sister couldn't take over the rest of the days so the owner decided to book another sitter on Rover. The sister met with the sitter, introduced the dogs, etc. The sitter couldn't start until later that day, though and the owner started to freak out. (Mind you, the dogs were totally fine in an air conditioned very large 3 story house with food and water). The booking with me had been cancelled hours ago so I no longer had anything to do with the owner/stay. Rover was informed throughout the whole process and was communicating with both of us. I had a set of spare keys and the owner told me to drop them off under the mat whenever I was done with my car but not to knock on the door so I wouldn't "disrupt the new sitter." This was a couple weeks ago and she just now decided to leave me a SCATHING horrible review that was several detailed and embellished paragraphs long. It was extreme and intense! She lied about almost everything and said I "abandoned her dogs" in call caps and to "beware" of me. She went on and on about how I'm a horrible sitter and person, etc etc. It's going to completely ruin my business and I don't know what to do! I've been on Rover for years and have gotten them thousands of dollars and dozens of repeat clients just for them to tell me they won't take the review down, even though there is proof they see in the messages between the owner and me that I'm not at fault and didn't abandon the dogs. It's even in messages that she told me not to go over and disrupt the new sitter! And that there was a sitter there and the sister! I'm at a loss and so angry and defeated. Rover isn't doing anything to help me!