Probably need a "Residence Certificate" from immigration, need proof of staying at least 1 month AirBNB, then TM30 from building Juristic or landlord, can still be difficult, try other branches, some Bangok Banks are often more amenable to foreigners?
I flew with EVA from Brisbane to Bangkok using Flight Center as agent, couldn't choose seats, when tried to book online was very expensive, however, from 48hrs before flight time, you can do web check-in online, choose seats then with no charge? Think probably same for you?
