And to add on to my earlier post, if this is your so called "terrible" service, wait till you fly some domestic carrier in US, you might even call it "flights from hell."
I think with the exception of the 15-minute call-button thing, which admittedly I have experienced on some of my flights (including SQ/CX for that matter, happens quite frequently on UA, never happens however on AN I notice), the rest of your flight should have been pretty much routine. I also admit that some of their cabin crew are arrogant, so CX's cabin crew is perfect?? They're humans too you know! They have to work for a living too and to serve passengers. You got what you paid for, passage from A to B and the rest is supplementary. You do not expect emperor's service when you haven't paid for that, do you??
Do you tell me CX's cabin staff are perfect? I'd really like to know! And if you're not happy with SQ, which you already knew before you flew, then don't fly with them!