No, it is not normal in Thailand. Usually the bank to which the ATM is attached will start an investigation if the ATM did not dispense the cash. As others have suggested, report the transaction to your own bank also.
"Is this normal in Thailand?"
You say that the ATM gave you your B8,000, you also say that it didn't. Which one is it and which bank's ATM did you use? "The Savings Bank" is not a Thai bank. Is it possible that you didn't make your problem clear to the bank staff, also? Is that normal for you?