Unacceptable, sorry this is happening. Do you know about fail2ban? You can have it automatically filter IPs that violate certain rules. One rule could be matching on the bot trying certain URLs. You might be able to get some kind of honeypot going with that idea. Good luck
They list a service for each address, so maybe you could block all the non-Route 53 IP addresses. Although that assumes they aren’t using the Route 53 IPs or unlisted IPs for scraping (the page warns it’s not a comprehensive list).
Regardless, it sucks that you have to deal with this. The fact that you’re a customer makes it all the more absurd.