why are some ISP's so damn diffuclut to deal with?

[SilverNodashi]

I'm just curious, why are some ISP's so difficult to work with?

We have a case with Hetzner, where one of their clients moved a few domains to us and it's been such a pain in the neck todo this smoothly. We've been trying to move these domains for about 2 months now.

First they say they'll release the domains, so we initiate the domain transfer and 4 out 17 transfer succesful. When our client queried this, they had all sorts of excuses about the transfer, but say they'll approve the remaining. 3 go through. And this patern keeps on 2 months down the line. 1 domain remains.


Another story:
Another client moved over to us, 3 years ago from Mweb. 2 months after the move their domain is still not deleted from the Mweb network, so whenever their clients (who uses Mweb as an ISP) can't email them (the emails goto the Mweb mailservers not ours). After many fights with Mweb, the client decides to leave the mail with Mweb. So they've been paying double for email hosting for 3 years now.


Yet another story:
A client moved over from @lantic to us, but their email to 3 of their clients who still reside with DataPro doesn't go through. I've been querying this matter for 2 weeks now, and all I get from DataPro is "Your mailserver is blocked", but no actually explanation as to why. How am I supposed to fix this if I don't know why it's blocked?