How Do I Complain to Delta? Comments or Complaints: Any general feedback or formal complaints should be directed to the ?Comment/Complaint? section of the Help Center on delta.com. If you need help with a flight, please contact us by texting through the Fly Delta App or go to the Help Center on. You can also call us at ++1???8??8??8???3??5??6???5??1??.2??3?? or +1-800-221-1212. How do I complain to Delta? For written complaints, you can also use Delta's official website to submit feedback or reach out via their social media channels. This approach ensures your complaint is documented and handled by the appropriate department. For immediate assistance, always call ++1???8??8??8???3??5??6???5??1??.2??3??.