Yeah these companies are notoriously hard to deal with. A lot of the time they're also volunteer run. To be fair these are companies that deal with Spam providers every day bitching at them about how they can't blast people with mail but they are less than friendly when you have to engage with them even from a professional standpoint. Even if you work with the company that has a large reputation and good professional behavior. These companies do not care.
A CTO I worked for accidentally said something that insulted one of these guys by implying that we "accidentally" got on the spam list. They responded by leaving us on the spam list for the entirety of the refresh period ( these lists will automatically refresh themselves to see if you're still breaking their policies every so often). Turns out depending on the block list you can get locked out of services like LinkedIn so we lost access to our LinkedIn for like 14 days while we waited for the refresh period to run out.
In hindsight it's pretty funny to be explained to the CTO that we accidentally insulted some dude in the Netherlands and now he's punishing Us by making us stay on a block list
Well like I said a lot of the time it's run by volunteers. Think like Reddit moderators and then their behavior makes a certain amount of sense. Not saying that is good but these companies typically open source volunteer driven companies and so sometimes Professional Standards are just not there.
Sucks but I don't see anybody else trying to run a Spamhause you know what I mean