I didn't make the rules either ! I have a DTV visa issued by the Thai embassy in London based on me enrolling on a course to learn the Thai language at a language school....simple.
No need for an agent....I walked into Bangkok Bank Nonthaburi with a Thai friend, which obviously helped with the language difference, showed passport and TM30 , bought the obligatory, but not essential accident insurance, and walked out 45 minutes later with bank account and debit card. Same with driving test...organised myself....pretty difficult to fail it. Perseverance is the key !!