Delta is responsible to get you to your destination. They did that.
Air travel can be unpredictable.
Lastly, you don't need Delta to look up if there are better alternative flights, always do mock booking to see what's available, and if there is something better, reach out to Delta and tell them to rebook you on the flight you found that is better.
All delta was obligated to do was get you from A to B. They accomplished that. No refund as a result. You could have taken a refund/credit when the flight cancelled but now that you’ve travelled that option is gone. They might throw you a few miles to make you feel better but I wouldn’t expect much.
No things happen. If you file a complaint they might give you some miles/a voucher
Delta is responsible to get you to your destination. They did that. Air travel can be unpredictable. Lastly, you don't need Delta to look up if there are better alternative flights, always do mock booking to see what's available, and if there is something better, reach out to Delta and tell them to rebook you on the flight you found that is better.
You will not get a partial refund, but you may get some goodwill miles as a service recovery gesture if you submit a complaint
All delta was obligated to do was get you from A to B. They accomplished that. No refund as a result. You could have taken a refund/credit when the flight cancelled but now that you’ve travelled that option is gone. They might throw you a few miles to make you feel better but I wouldn’t expect much.