Sorting through all the different currency rates is a challenge and after a while you find the the Australian Exchange rates for both Bangkok Bank and Siam Commerical Bank. There are also different rates for different ways you can do foreign exchange:

D$/$D: Direct Debit, TT: Telegraphic Transfer $($both electronic forms of FX between bank accounts that you does not apply to you as you have bank notes to change$)$

Export Sight Bills: For international trade $($not relevant to you a tourist$),$ T$/$Chqs: Travelers Cheques $($not relevant as you have bank notes$)$