Lol good luck with that they dont know what that is.

Time consuming, frustrating and pointless. It's extremely difficult to get to them, and they really don't want to help customers. They're there just to give the impression that support is available. If you do get through be prepared for a bunch of insincere hollow platitudes and responses that just go round in circles.

Not easy, there chat is completely automated and always busy.

It is very easy to contact Blizzards customer service. But they don't seem to value customer satisfaction at all

Practically impossible. You can get a macro response from someone who probably doesn't speak English if you really want to, but that's about as good as it's likely to get.