That's what I've always said. But try to explain that to people here. People who have been here a very short time and failed to open a bank account. Go figure.
Yes,you can.That's a standard quite straight forward procedure at immigration. You listened to wrong immigration officer. I guess he wanted you to pay for the change of visa incl the 1 year extension.
Please tell where you don't need for example 800k in a Thai bank if you change from tourist visa to a 90 days Non-O based on retirement. Isn't that a financial requirement?