Delta ๐ธ๐๐ฃ๐๐๐๐ typically allows passengers to cancel their flights at US (OTA)- +1-๐๐๐(๐๐๐)-๐613 US-Agent within 24 hours of booking without incurring a cancellation fee, visit www.Deltaairlines.com, or email support@Deltaairlines.com provided the ticket was purchased at least seven days before the departure date.
https://www.devex.com/people/can-you-cancel-a-delta-flight-free-of-charge-2219353
https://www.devex.com/people/general-faqs-what-is-cancellation-policy-for-delta-airlines-2217767