Unfortunately every office has different rules and every immigration officer goes by his own set of rules haha. Go another day and it all could be different. That's why we love Thailand TIT
First we don't know what country you are from but if you have 30 exempt now, I'm guessing you can get another 30 days at immigration. 60 days is not possible unless you leave and go to another country and try to get 60 visa and then return or apply in you home country. Not sure how 6 years ago you did 60 day extension.