And just to clarify in the situation - full hotel
booking used.
We all checked out as expected and at the right time. We all went to the airport at the same time. I departed on a one world flight in the opposite direction to the rest of the family so it was purely the single return flight seat that was not used.
I even asked BA to recost my return flight on the holiday to return home ‘via’ the business destination but they did not want to do that and advised me just to no show. 🤷♀️