What documents are required for a retirement visa extension in Thailand?

I Hit a few hurdles with a marriage visa extension so I am thinking about applying for a retirement extension. I have the money but could somebody please list everything I need to present at immi office. Dont know if others have faced this but today I was told that stamped bank statement was insufficient now I need a letter from the bank confirming my address and status as a customer. I only have four more days so please if you are not sure dont say. I appreciate help but Ive not got long