My experience was similar to that of 1353513636.
I tried calling from North America # times, only to get a busy signal each time. Today, I managed to get a live agent.
My issue got resolved. Misconnect in LIS as a result of a cancelled flight. Here is the thing..........to do so, I spent 1.5 hours on the phone - most of it on hold!
Seems that TAP Customer Service is poorly staffed.
I don't know about the FB strategy? Here is what I know does not work...........I tried emailing them # times. Either they did not reply - or - the reply was non responsive.
Lessons learned..........keep trying?