If you do not have a name, Dear Sir/Madam is acceptable in the salutation line. Don't forget to end your complaint letter with a closing salutation such as "Yours sincerely" or "Sincerely" and to leave sufficient space for your signature (usually three lines).
CLOSING PARAGRAPH
I hope that you will deal with this matter promptly as it is causing me considerable inconvenience. I feel/believe that I am entitled to a replacement/ refund… I demand a full refund/an immediate replacement/etc or I shall be forced to take legal action/ the matter further.
Use a kind and professional closing
Keep your tone positive, so they feel motivated to find a solution. Then, use a professional closing, such as Sincerely or Thank you followed by your name. Maintaining proper etiquette throughout your email can make you seem more professional and approachable.
Sign the letter with a formal closing such as, “Yours truly,” “Sincerely,” or “Respectfully” followed by your name. For product issues, say something like, “I'd like a full refund or replacement.” For other issues, consider something like, “I'd appreciate your immediate help and communication in resolving this issue.”
Be Professional
Remain calm and composed, and reference the notes you took about your feelings and specific incidences. Describe the situation and how it has affected you, and state that you would appreciate it if changed were made to fix the problem.
The preferred letter ending phrases for formal, social, or business correspondence are “Sincerely,” “Sincerely yours,” “Very sincerely,” or “Very sincerely yours.” “Kind(est) regards,” and “Warm(est) regards” fill a nice gap between formal and more intimate closings.
As much as I hate to see you go, I completely understand how upset you must feel. I apologize again for any trouble we may have caused you. Good luck with your business, and I wish you all the best. Let me know if you have any more questions, comments, or concerns.
Your last paragraph should sum up the major points in your letter, provide necessary final thoughts, and suggest possible follow-ups and next steps. It's important to strike the right tone for your goal. If you're trying to motivate your recipient, you don't want to send wishy-washy and uncertain.
Best regards
This email ending is slightly less formal than “Kind regards,” but it's still a safe bet for your business emails.
Regards, Best regards, and Kind regards are good email sign-offs. Remember that concerning and about can work just as well as, and more concisely than, in regard to and with regard to. The phrases in regards to and with regards to are never correct, and you might garner criticism if you use them.
“I always say 'thank you so much for your time,' or 'thanks in advance' if the purpose of my email was to ask questions or if I'm providing instructions on a project to someone,” Camejo Sanchez says. “Expressing gratitude and kind regards is always a good idea!” Professional email sign-off examples include: Sincerely.
Even though you might not be aware of doing so, passive-aggressive behavior can negatively affect your work relationships. As a matter of fact, it's important to avoid passive-aggressive email sign-offs such as: Regards.
If the letter is to a supervisor, someone you've never met or someone you don't know very well, choose a formal and professional ending like “Sincerely,” “Regards” or “Respectfully.” If the letter is for someone you have interacted with frequently or know well, then you may use a more informal closing while still ...
Your closing signature will include the complimentary closing word(s) — “Regards,” “Yours truly,” “Warm wishes,” etc. — followed by your name. You should include your contact information at the top of the letter for hard copy letters and letters attached to emails, so it doesn't need to be in your closing.
“Best regards” or “Sincerely” are generally safe choices. Keep your tone consistent. Don't be overly familiar or casual in formal business correspondence. Follow up the close with a comma.