You should send an e-mail or mail a typed letter to the business's customer service department and state specifically what you did not like about the service you received there.
Write a letter with return receipt as proof that they received it. You can send the letter to the office manager if a lower level employee caused the problem. Send it to the professional if it is a doctor or lawyer.
Ask for a form in which you can offer your feedback. Then list your complaints. Other than that you can give yourself time to write a letter to the owner of the company.
