Excuse me, but how hard can it be to understand that you just need to show financial proof back home? Next step when in Thailand, you'll need money in a Thai bank account.
How much is "so much money"?? This might be a longshot,but have you tried in a mall where they usually have almost every Thai bank? It has for some reason worked out for a lot of people on tourist visas. If it works today? To be honest,no idea.