Sorry what does it mean by 1 minute block and pet second billing?
That means if you go call another party and say "Hey, help me buy a coke from 7-11" and your friend replies "Ok" and hang up, you will be charged 1 minute, een though the above 2 sentence you can finish it within 30 seconds.
Per second billing means your 100 minute ($39 basic plan), 300 mins ($59 medium plan) and 700 mins ($99 high plan) is really given as such.
Check your handphone next time when you hang up, some short calls like 0:00:30 will means you have used 1 minute for Singtel and Starhub which is a problem when you make a missed call that diverted into this message: "You have reached...." and you just hang up immediately.
And for 6 second billing, something exclusively for Singtel, it means that if you make a call of 1 minute and 2 seconds, you will be using 1 minute 6 seconds. The 4 seconds per call means it will cheat another minute with 15 such calls.
Hence, the problem with Singtel is that their plans are always lower talk time (200 min VS 300 min for $59 plan, 500 min VS 700 min for $99 plan), but more easier to utilize up and always by $0.90 to $1.80 more expensive than M1 / Starhub.
Yes, who uses that much SMS nowadays with WhatsApp which is something Singtel good at?
Even for $198 unlimited call 12GB plan, it comes with 2k SMS. Singtel one is $239.90 for unlimited plan. So for the difference of $41.90, it means that one needs to make 2838 SMS per month in order to break even.
So
no one in their sane mind should
ever use Singtel once it is out of contract unless they uses 2838 SMS per month. However, Starhub's Elite plan is so unattractive as it is the only elite plan that comes without unlimited calls and yet caps the SMS at 2.5k for 12GB data.
Hence, Make the right choice and join the M1 or Starhub (Unlimited plan) revolution now.