Not necessarily, it depends on the type of plan the OP is on, and what their accumulated top-up position was at the time of the last top-up.

http://www.12call.ais.co.th/en/Conte...nit/index.html

For those who top-up frequently they eventually get to the point where any typical top-up adds 30 days and extends the validity to a maximum of 366 days.

The OP probably only did a few top-ups so maybe was in the 60 - 120 day range when they left? Again just a guess, *121# should give an accurate picture, although I'm not sure if you had to enable international roaming first?

If *121# doesn't work (it always works for me), then pop an email to [email protected]

You can also call from a phone (other than your mobile) 011 66 2 271 9000 for customer service.