Dear Mr. Ken,
Thank you for your letter dated 01 Sep 2xxx. I apologize for my overdraft not realizing I had a debit balance in my account.
This debit balance occurred because a check of USD500 from a customer of mine had not been cleared yet. Anyhow to correct matters, I have transferred USD500 from my savings account to my current account so that my balance will not be in debit.
Thank you for allowing the last check to pass despite the debit balance. I will make sure that there will be no repetition of this.