Hi wamonkol,
Greetings! Thank you for posting in Microsoft Community.
I'm sorry to hear about the bulging issue on your Surface. I can feel how important the device for you as a student.
We do not have an authorized repair shop in Thailand. In this case, you need to reach out to the Customer Support to get an assistance about how to proceed with the repair.
Please contact the customer support team in your Country through the numbers listed in Global Customer Service phone numbers (microsoft.com) under For Business users. This works with Home users also, just select Surface then Home as a type of user in the IVR prompt.