Platinum medallion, but irrelevant to the story. I was booked on a single ticket FCA-MSP-ATL and had a misfortune of getting stuck in ATL on the plane for 4+ hours after landing on March 6th. Although by the time we exited the plane it was already the morning of the 7th.

Received an automatic 250 USD voucher and an email that said "...While weather-related disruptions are beyond our control, we recognize the impact this had on your travel experience. As part of our commitment to service recovery, compensation has been issued as a gesture of goodwill, and we will also be refunding your flight once your travel has completed."

Upon asking for a refund, Delta is saying I am only entitled to a refund of MSP-ATL and not the entire journey? Is this a fair assumption or are they incorrect?
Additional data point: two of my friends traveling on the same flights received a full refund.