On a social network like that, where anyone can see and partake in any conversation, asking an open question or reporting any kind of issue makes it impossible for companies to ignore. Sending them email and getting no response could result in me getting upset, maybe changing company and telling my friends, majority of who won't do anything in regards to that. Exposing company for not being helpful or service disruption can escalate quite rapidly on networks where people can share your post without much effort, regardless of the fact if it's true or not.

So, I abuse that fact. I don't send them DMs I call them out publicly. It's so stupidly effective.