Experienced DevOps with AWS and HAProxy knowledge needed (using AWS to spin up fresh batch of IPs)

I run a small SmartDNS service, and one the of the services has stopped working. Normally I can manage fine on my own, but I'm having a tough time getting this one work to work correctly again.

It seems the service in question blocks certain IPs that are being used for customers when it notices too much traffic coming from them. I had a pool of 400+ IPs in a HAProxy setup which seemed to do the trick for several months, but it has since stopped working.

I'm thinking a different solution needs to be implemented. Perhaps a new AWS or cloud instance can spun up every so often with a dedicated IP for each request, or maybe each user, flushing a pool of IP addresses every day, I'm not sure from a technical standpoint what sort of options are available here, but I need some help.

I had someone begin work on creating something like this, but he had to forgo the project due to a family emergency. He had begun work using CloudFormation. You can use what he's configured to date or start from scratch if you'd like.

If we can figure out a solution together, I'll certainly have more work for you in the future.