How to write a note of apology
I am writing to apologize for my failure to call on you at the office as planned.I've been preoccupied with writing my course paper these days and simply forgot about our appointment.I am extremely sorry for any inconvenience I may have cased you . In the future I shall try not to miss any more appointments.
I am very sorry for not answering promptly. I am busy making preparations for an arts exhibition to be held at the beginning of next month. I understand you will forgive me for any inconvenience my delay may have caused you.
By the way,are you interested in our arts exhibition? Your presence would be welcome.