This was the case before the pandemic. About 5 years ago, I booked a Delta Vacation trip and wanted to add a car. After on hold for hours, I finally hung up and never got through to an agent. Booked a car separately instead. From that experience, I realized that while Delta Vacation can offer incredible prices, don't expect to talk to any agents unless you are booking a new vacation. I think the prioritize calls for new trips over the ones they already got your money. I would, too.