Apologizing for a delay in answering a complaint

Miss P Jones 66 River Way Ottawa - Canada Dear Miss Jones, I have your letter of 1 March. I am very sorry that your previous letters have gone unanswered. I must confess that I personally never received them. I am currently investigating the reason for this. I note that you took delivery of our model PC200 and that the User's Manual was not included in the package. I have dispatched the Manual under separate cover. It should reach you within 10 days. I apologize for our original error and the unfortunate delay in answering your complaint. Yours sincerely,		Useful phrases Line 1 I am very sorry that your previous letters have gone unanswered. Line 2 I am currently investigating the reason for this. Line 8 I apologize for our original error and the unfortunate delay in answering your complaint. Notes Para. 1 Acknowledge the complaint. Para. 2 Refer to the missing goods. Para. 3 Say what action you have taken. Para. 4 Apologize for the error and the delay.
Comments The letter politely accepts the complaint. The company apologizes and takes steps to remedy the problem.	Alternative phrases Line 1      ... that we have not answered your letters. Line 2      At the moment, I am investigating . . . Line 4      ... that we did not include the User's Manual . . Line 6      I have sent you ... Line 6      You should receive it. . . Line 8      Please accept my apologies for . . .