I no longer have the sim card - after 3 hours of not being able to get it to function AIS refunded my money
IIRC AIS set the apn to internet and aisinternet. Setting did not specify 3g and I don't think they changed the apn type (I think it was blank - maybe that was the problem.
I went to AIS store at Big C (small one which then referred me to Central store- which is where I spent an hour more and they ultimately gave up). Had purchased top up at the one in term 21 - but hadn't used it right then - since it was a card I already used and I got a message that I had 1g I didn't try to use it until a few days later.
I later went to the AIS store at ICON to see if I could try one of their sims - they let me, it didn't work, but they seemed to have little/no interest in trying to get it to work.

What phone do u have?