I see that the 21st Century has caught up with our transport companies.
Under new National Transport Authority rules, they have to respond to complaints made on Twitter within one hour. Emails are given a day. I wonder why, but then again, there's nothing like a public forum to give a query an edge and on the whole, I've found @DublinBusNews and @IrishRail a good responder on Twitter.
Other organisations which manage to blend a good mix of engaging with customers while getting good quality information out on social media include @meteor_mobile and @vodafoneireland. I particularly like the often funny/madly serious tweets by @GardaTraffic and they're excellent at responding to individuals too.
When complaining on Twitter, keep it tight (140 character limit helps!), don't be afraid to DM if asked and don't be abusive. You'll get a better response if you engage sensibly.