@Gar****
that's a debit card fee then, they are usually charged annually. That's not an account maintenance fee. It's also on the high side, but if you have a card with accident insurance, it could be 600B/year. Most regular cards are 200-300. If you didn't have the card, it would be zero.
The rules about inactive accounts and maintenance are set by the Bank of Thailand and are the same for all banks- after one year of inactivity, IF the balance is below 2,000, they can start charging a monthly maintenance fee of 50B, until the account is empty.