@Bob *********
totally correct, you got OFF the OA extensions and went to a new O visa (probably because you didn't want to mess with the insurance)
Unfortunately for getting the initial 90 day non-O visa OR getting the first yearly extension on it you CANNOT use monthly income method. That's just how it is at EVERY immigration office.
you can do it next year though, but remember you still need to meet the seasoning requirements for your current extension on banked money which are you need to keep the 800K baht in the bank for 3 months after you get the extension granted and you can't let the balance go below 400K baht the rest of the year AND you also need to transfer in to the country a minimum of 65K baht a month for 12 months too