I did this process in November. It was recommended to me to email and/or call. I did both and after talking to the Thai pass people, I was approved within 30 minutes. Maybe this will work for you.
My 30 day extension expires Jan 30th. I went to immigration In Jomtien on the 11th. I applied for a 60 day Covid extension. They stamped my passport under consideration and a return date of Feb 8th. Most people are reporting a return date of the 24th or 25th. I have no idea of why my return date is past my extension date. All I can advise you is to give it a try. Get there before 7 am.