Indie publisher here. Sorry to hear about this. Among the numerous frustrations that publishers and sellers report when dealing with Amazon, automated lockouts are near the top of the list. Inability to get a clear explanation or knowledgeable human support are close behind.

I always tell other publishers that Amazon's seller tech is like a rickety roller coaster with lots of kludged together components - built to go fast, but with lots of loose bits that rattle and sometimes cause the system to fail. Technology glitches, bad UI design, poor communication, and complex policy requirements lead to a huge support burden. Even if you can get a good Amazon support agent, they are not always able to diagnose certain problems, let alone provide a fix.

The parts of the company facing small publishers and third-party sellers is extremely siloed, which makes things even worse for sellers trying to get through complex issues touching multiple services. Reporting something like "I can't get Amazon Advertising to connect with my KDP account" can lead to runarounds that require multiple tickets or are never solved.

Regarding distribution: I don't use a distributor owing to the lead time required and the huge commissions involved, but a few I know work with IPG (https://www.ipgbook.com/). If you have a track record of sales, that can open the door to distribution and potentially help get through the Amazon problems you are experiencing as they have direct contacts with back-end Amazon staff.