Dear
When I received your letter of (date) with my checkattached marked “insufficient funds”, I called my bankimmediately.
The gentleman I spoke with, (name) , discoveredthat the bank had failed to credit my account with asubstantial deposit I had made several days prior.
The bank has assured me that they will be sending you aformal letter of apology for their error. Attached is mycheck in the amount of $ to replace the dishonored one you have returned.