As a counterexample, I've gotten great service from very large companies by sending them private communication via social media (Facebook messages, for instance

As a counterexample, I've gotten great service from very large companies by sending them private communication via social media (Facebook messages, for instance) - mostly because I really don't want to fill up my social media feeds with whiny complaints. I mostly do it because it saves me driving in and/or waiting on hold, but those messages usually seem to be answered by the same team (and are generally handled very well).