Send a dm on twitter and request for a call back. I would keep the detail to a minimum as the social media team can create and resolve Customer relations issues and cases.

in regards to Youfirst they should have created a cr case and escalated it as priority. At any point did the csd/CSM speak to you during the flight, did you raise any issues with them regarding onboard service, Ife? If they didn’t I am not surprised all my flights from lax Lhr have been poor....