Had to call for two trips out of 4 booked. Return call on Diamond Line promised in 36 minutes, received in 26 minutes:

1. Canceling DEN-LAX on 3/17 was simple, though I had to acknowledge that it was due to COVID-19. Received credit, which is no issue considering my anticipated nearly weekly travel.
2. With schedule upload, my return flight (STL-DEN) on 4/11 has 'disappeared.' The agent said it was still operating, but blacked out from future bookings. She dug deeper and saw plenty of seats (shocker). At what point, will DL concede that the route has been suspended so that I can amend the entire booking? I'll have to change outbound based on uploaded schedule to make this trip work. Obviously, not urgent, but it crosses Easter weekend, so I'd rather be (more) proactive than usual with that trip.