I was scheduled to fly AXA-SJU-JFK on DL. Schedule changed from 2 hours (original) to 6:15 layover.

I asked DL (via chat) to change to the nonstop SXM-JFK. They wanted to collect ~$200/person change. Was surprised since this is a DL-initiated change and since SXM and AXA are 12 miles apart (albeit over water).

Is DL typically this inflexible when they've changed the schedule? Should I try again via phone?