Dear K' Siwapat,
Thanks you for your email krab.
I have just called you, and I think you are busy, that why you did not receive my call.
I am writing to you to invite you to have a meeting with Dr Narong on tomorrow morning at 9:00 AM on 30-Sept-2015 at FEC office. He would like to discuss with you about our further business.
Please confirm krab.
Thanks you