Dear Sir,

I hope this letter will find you well. It is shame that I have made such a terrible mistake with you and feel sorry for that …

First and foremost, I would like to personally apologize for your inconvenience. Moreover, it is also my fault that...

Secondly, even if it is an unforgettable event in my life. I would like vanish
my faults by ….. Furthmore, another piece of good news is that...

I hope that you would take into consideration and accept my apology as it
is highly necessary for me.

I look forward to receiving from you,
Yours faithfully,