Glad this all seems to have worked itself out.

A good while ago now I arrived at T5 late (33mins before flight...) because HEX was out and tube playing up.

Went to see what BA could do and got an apology which I thought would be followed a request for a large sum of cash but instead it was that the next flight available wasn't for a few hours.

Rebooked gratis and all sorted out in less than 10 minutes. I was amazed but shows there can be benefits to sticking with BA I guess.