Phrases Complaints and Suggestions

I have a complaint about...

Meaning

Formally stating a complaint.

John: I need to speak to the manager.
Alice: Certainly, sir. What seems to be the problem?
John: <b>I have a complaint about</b> the service I received.
Alice: I apologize. Please tell me more about your experience. Perhaps we can resolve the issue. If you'd like to submit a formal complaint, <b>I have a complaint about</b> the way this is being handled.