It's designed to stop the agents using the banks to obtain their dodgy extensions. The bank knows many will withdraw the money immediately the extension has been issued. If immigration are saying "nothing to do with us" it's probably time for immigration to call "last orders" on these dodgy retirement extensions
I don't know. To be honest, I've never bothered to get a Thai licence as I'm in and out of the country on a frequent basis, and try to steer well away from ties to Thailand for taxation reasons