Ok now so after the email that I sent straight to their CEO, Lifemiles finally decided that they wanted to be rid of me by getting me satisfied - they gave me two straight calls yesterday (first one at 3am!) and offered several options, which I accepted one of them and ticketed this morning. I can only assume that the email address I guessed was a right one so he got straight onto it - well done Matthew!
So one thing I noticed is how they can see far more availability in their back-end especially on SQ, as none of the flights they offered to me are available online!
I ended up booking BR-SQ NGO-TPE-SIN-SYD with options also given for SQ KIX-SIN-SYD and none of the SQ flights were available on LM at the time of checking (both a couple days ago and yesterday/today).
Ended up on SQ231 so guess I'll give them a rest for now!
Ps. One of my friends who also had issue with LM (they also refused to ticket his requests from MEL to FRA and return, despite no issues with all the flights) received a proactive call from LM last night, I can only assume as an aftermath of what I sent, and they ticketed his itinerary without a single change.
Cheers,
Michael