Check with the embassy that they actually accept the bank certificate. I provided a bank certificate to Taipei and they said they do not accept bank certificates. I pointed out the financial evidence detail in your OP, but they would not budge. Luckily it was an in-person application, I was able to rush to my hotel and get a bank statement printed out to avoid a rejection.
A cert of employment and income statement along with a letter detailing teaching non Thai students plus the usual CV, bank statements with income deposits etc