For non-urgent matters I usually turn to twitter. Things like schedule changes days in advance, etc.

On my last trip I got lucky that I was able to resolve things after my reservation got borked after I was not chosen to be bumped for a voucher. I landed airside at 5 am in CLT without my connecting flight showing in PNR and no boarding pass. No airside desks were open that early, finally got through using the chat in the AA app. The agent in the in app chat managed to restore my connecting segment but could not check me in because it was then too close to flight time. Luckily I was able to check in at the gate before the upgrade list cleared. What's worse is the upgrade had previously cleared and whatever happened had knocked me out of the first class seat and it was sheer luck I re-cleared into the last seat.