Update: So finally I ticketed the Air India award I wanted to book. I was pleasantly surprised to receive a response on my email in a couple of hours. Then someone with an
exotic South American accent called me from USofA 
; provided me with availability, took my card details, and boom within half an hour I had the ticket in my mailbox. I still pushed them to search for an award availability on Swiss, because I could see that on United and Aeroplan (but not on LM). But as I was expecting it, they said they can't see any availability on Swiss metal.
All in all, I would say my first time experience of dealing with LM customer support to book an award, wasn't too bad. Before this I have only dealt with them once, when I emailed them to credit miles retrospectively for a travel on TK. Even then I was pleasantly surprised to have received a response on the same day of my email, and that too not a canned response! They actually credited miles to my account the same day I emailed them, which I don't think I have experienced with any other FF program. With such kind of experiences, I am not sure why I see moans and groans all around, on the Avianca forum on FT!
But I trust you peeps here, so I assume I just lucky both times. Touch wood!
Anyway, there is something which you peeps can help me with. LM quoted me $25 more in taxes, than what I could see on their website. I tried arguing with the agent, but he was like "take it or leave it". Since I needed this ticket desperately, I agreed to pay $25 more. But please can someone tell me what this $25 charge is? Is it a levy for booking through the call centre, like what Alaska does?