มารุต บุนนาค

In case that the application of your company for Promotion Certificate was rejected by B.O.I., you cannot appeal to the higher level because the B.O.I. is like an independent entity.

However, you can take a legal action against the B.O.I. in the Administrative Court on the basis that its decisions are related to the discretion and opinion of its officials. 

Nevertheless, it may not worthwhile to take legal action because it will take a long time. It would be better to submit a new application in accordance with the requirements, rules and regulations of the B.O.I. which would be easier . If you are not sure how to proceed, then consult with your lawyer.