An Apology letter
Dear Mr Alex,
I regret to inform you I will not been able to start the course in time. It was due to reasons entirely beyond my control. Please be assured that I will resolve the issue in the near future. I value your custom highly, so I would like you to enter me in a list of the next month course.
I hope to hear favorably from you. Please accept my apologizes.
Yours sincerely,
Ann Nett