I am concerned about your statement regarding the Bangkok Bank. All I required to renew my retirement visa last month was my Bangkok Bank savings book showing the balance of at least 800,000 baht plus photocopy of title page and of the balance going back at least 3 months - + a letter from the bank which authenticates you as a customer and which cost me 100 baht - but the date on the letter should correspond to the last update shown and ought to be within 2 days of application/submission. Of course there are all the other bits and pieces - residency form, back copies of recent visas, last exit stamp plus the forms accepting liability and punishment etc. There was no problem at all. I hope this helps