Anonymous participant 535 like I said, further you go from touristy places, the less the branches are “subject to strict rules”
You have to understand that the government is clamping down on foreign accounts because of money laundering - and where are most of these foreigners? In touristy areas - and thus those branches are the first to get targeted.
Go to a different branch, preferably in a different region/city. The further you go from touristy branches, the easier it will be. Helps if you speak Thai too.
I did whatever you did, not even having a visa, and they did it for me without even asking for any documents.