This was on another thread, but I can't find it, so I'm starting a new one. If you don't have a credit card, someone said you could use a debit card (must be VISA) issued by a Thai bank. I tried this, but it failed, because my Krung Thai card was a 'swipe through' type (I thought all ATM-friendly cards were that?)
The next stage is to get an International Banker's Draft. You cannot get this in Buriram; I tried Siam Commercial and Bangkok Banks, and both said 'Korat". I got a friend to buy it in Chiangmai, where the banks are bigger... and have more senior staff... because the key is that someone in the bank must be able to sign on the bank's account in the currency where you want your draft. That means for a British Passport, they need a signatory on an account in Hong Kong.
Difficult? Oh no, the change to the new system was made for the customer's convenience!