I’m in the same boat, travelling 6th May and was told on Saturday I’d be contacted Monday or Tuesday by the upgrades team. Sent an email Sunday evening with proof of travel and had the same automated message of being contacted within 48 hours. I phoned this morning and got the most unhelpful person who sounded as if he was half asleep. He said they’re running behind on call backs, typical. I’m literally drained with the whole thing!