Hilarious. How many times did the OP ask to be upgraded? No wonder the CSM lost her rag! They did a nice thing, some people had a good time, the OP sat in a nice seat. The OP could just smile and enjoy some people being made happy if they chose...They lost nothing. I know if I was part of a party and upgraded it'd make my day, and I expect that's what the captain thought, not realising someone would be simmering over it and actually try to get staff reprimanded for nice gesture.
If anyone else was on this flight I genuinely suggest writing to BA in support of the staff.