Have just returned from LHR/SYD return in F and was overall very disatisfied and am seriously considering changing my allegiance after 4 years a PPS. I list the main problems not in order of gravity.
1.On 2 separate flights they did not have the choice of main course I wished and considering on one of these flights there were only 6 passengers I found this unacceptable. Generally food not great as compared to previously
2.SQ F SYD lounge had no hot snacks or soup as they always had and there was another local Australian sparkling wine but no champagne.
3. Seemingly one person in economy who had severe nut allergy so there were no nuts on board and satay and macadamia nut ice cream were withdrawn from the menu. Surely they knew the person was in Y so why couldn't they be served in J and F?
4. Faulty heating system had only 2 settings like a sauna or freezing. It was the latter for the 14 hour journey. My wife and have never had such an uncomfortable flight. Not only that the way it was handled by staff was very upsetting. They never made a public announcement and only when pushed said they were sorry but it was understandably out of their control. They never went round offering extra blankets but had to be called.Why this wasn’t fixed before the plane left Singapore was never explained.

All in all a very unsatisfactory trip. I can now get a cheaper CX F fare LHR/SYD and reaching Solitaire will give me personally no extra benefits.

I intend complaining about the above and wondered if the best method is as STARG said using the SQ's feedback. Someone was also going to write their local PPS coordinator in Germany. Which method would be best? Anyway I've no idea of the local PPS coordinator in the UK.