Better get that bank account with 400,000 baht in asap you need 2 months so already you are on overstay so you Better get it sorted, then for the next 12 months need to deposit from an overseas account 40,000 baht each month, if not just leave the 400,000 in the bank, dont spend it.
Yep its very hard, my wife wouldn't take no for an answer, the branch managers are unable to make a decision and leave it up to head office in Bangkok. It can be done but you will need to shop around and have a wife that knows how to sort them out.