I almost missed my flight Bangkok-HKG because airport check-in staff told my visa to Hong Kong was no good. So I envaded the airline manager's office and sat there until he called HKG immigration services. Of course, there was no response (late evening flight), so he just let me check-in at his risk. When in HKG I wrote a letter to the Immigration Dept. about it and they sent a letter back confirming that my visa is valid.
I am conserned this might happen again. Shall I carry this letter with me everywhere? What would I do if I missed my flight?