I'm sorry for you experience and that bathroom/restroom was disgusting. Having done that particular flight in Y I vowed never again (Club World not that much better). BA use the oldest BA 772's on the flight, plus other routes. I now have travelled with Qatar, Ehitad, Swiss. all offering a better experience. As said vote with your feet and give your cash to other Oneworld airlines to use your status of be like myself travel with what timings and airlines you like or want to try, you won't be missed by BA I know that first hand.
John