In Chang Wattana they are strict and have a doctor evaluating these extensions.. u need to admit to a hospital, take a picture with. Eg. Today’s Bangkok post with staff bed and room, and then send somebody to say you can’t leave. Sorry that’s how it is. Or you use an agent !
The law is very clear. A foreigner have to be able to open a bank account. There are several cases where this is a requirement even to get a visa But practice is different ! Unfortunately