Dear Mr. Charles,
My errant customer, Mr. James of Excel Trading Co., still has not settled his debt. So, as we discussed over the telephone recently, you may go ahead and send him a letter asking for payment. I enclose Photostat copies of our invoices and reminders to him. The total amount is USD1000 which is overdue by more than three months.
As all conventional methods have failed to make him pay, perhaps a lawyer’s letter will bring him to his senses. If this fails, then please take whatever legal steps necessary to recover this debt. Thank you.