I paid 1,600 B fine for not having TM30 and 1,900 B for 30 day extension. They give you a slip to show you have TM30. Copies can be made right next door.
I did this in CM 3 weeks ago and my wife had to join me via taxi because they told her she (I) had to pay a fine of 1,600 baht. You need to have the TM30 slip or a copy of it in your passport to get the 30 day extension. If you don’t have that they will send you to a building behind the main office to get one. CM seems to have relatively strict enforcement of the rules. You can’t skip the 30 days and go straight to the 60 as far as I know.