They need facial recognition pics to be taken. I had the same issue. Was not my sim card or phone or passport... they needed to enter my picture. They took it at branch. But did make we come back the following day (AM). All worked right away though. Yes a pain in the backside... and rather silly really.
Don't believe people who say they will not know. 10 years ago maybe. But today they will know. However being Thailand you might slip through. But again... don't count on it.
Wait everyone.... not a law yet and they are still figuring things out. Don't panic. Agents are on the case and will sort things out. It is what they do and know the rules. This is Thailand and things always seem to be announced and then a month later disappear... maybe to do the same thing over again with same results. Take the TM30 panic... the tax I'd requirement... the up and down of the DTV... etc.