Alright, API support tickets are officially the worst thing ever.
I mean, occasionally I'll email in to a company's API support, with an issue like "Hi, I'm getting a 500 internal server error trying to access this resource on your server" and provide as many steps to reproduce as I can (which in this case, would mean providing the URL I'm hitting, all headers I'm sending, and if it's a POST or PUT request, the payload. Sometimes a Fiddler .saz recording.) And because the issues I email in for are for sure issues on their side, and I provide full steps to reproduce the error, it's usually a one and done deal: I send in one email regarding my issue, and eventually I get one email of response saying "hi, I've found and fixed the issue"
Unfortunately emails like mine are a sad minority of API support cases. I'm working with this guy trying to use our API, on a ticket over a 401 Unauthorized error, with several emails back and forth, trying to get him to understand that a 401 error means the credentials they are sending are incorrect, that I can access the system just fine with the credentials he's sending me, that we haven't changed anything, etc. But he keeps insisting that they haven't changed anything, and that something is wrong on our side.