Booked a VS on Premium Economy flight later this month through a well-known OTA. However this morning I got a pretty drastic schedule change. Flight was due to depart at 20:00-ish from JFK and now is departing at 08:00-ish from JFK. Thus causing a nearly 24hr layover at LHR.

I know VS expressly says that it doesn't provide support when things are booked via an OTA. Other than contacting the OTA, are there any other avenues to explore to cancel my flight. Not sure if it helps, but I am Delta Diamond (however there are no DL segments on the reservation).