On most Thai Embassy websites it is told very explicit that Passport information must be absolutely exact, and if not so, application will be rejected, and the visafee is lost.
Nobody can change Passport information.
So only one to blame, yourself.
In fact the Belgium Thai Embassy IS very explicit:
“3. Fill in the Application Form
Please exercise caution when filling in information such as first name, middle name, last name, date of birth, passport number, and other passport details (Examples here). In addition, please make sure that all information is correct before submitting because we cannot adjust anything. Double-check all information, especially if your device is using auto-fill or auto-correct. “