Yes it is possible at CW.

In fact I just did it there last week.

The fee is still 1900 Baht.

Copy passport I.D. page downstairs and arrival  stamp downstairs in copy shop.

Photos (packet of 5 photos is 100 Baht) 

Fill out form upstairs, sign it, and get queue ticket.

Wait until called and pay fee of 1900 Baht.

When called again collect passport with 30 day extension

I am extended until 27 July 2017.

On 6/20/2017 at 1:56 AM, BritTim said:

For a denied extension, you basically just need your passport, completed form with photo and 1,900 baht. (Maybe, evidence of TM 30 in some offices.) Since you do not qualify for any extension, there is no supporting documentation to support the application.

Thank you very much for your response BritTim. My visa exempt extension expires on Saturday which I naturally won't be able to go on because it's closed, can I go on Monday and not have overstay or does it have to be Friday?

7 minutes ago, steveharrisisthelegend said:

Thank you very much for your response BritTim. My visa exempt extension expires on Saturday which I naturally won't be able to go on because it's closed, can I go on Monday and not have overstay or does it have to be Friday?

I am unsure of the answer to that. When entitled to an extension, you can apply on the first working day after your permission to stay expires when that is a holiday, but that may not apply when you are not eligible for an extension. Surely, it would be better to go Friday.

1 hour ago, BritTim said:

I am unsure of the answer to that. When entitled to an extension, you can apply on the first working day after your permission to stay expires when that is a holiday, but that may not apply when you are not eligible for an extension. Surely, it would be better to go Friday.

Ok. Thank you very much for swift response, BritTim. I will go tomorrow then. Have a good day!