How to refund Frontier Airline tickets when non-refundable but have Expedia Protection Plan?

I just recently bought tickets for this week Wednesday-Saturday LAX to DFW. I bought it on Expedia with my hotel and flight as a bundle and with the Expedia Protection Plan. The plan guaranteed that I could get a 100% refund.

However, when I tried cancelling them, it said I could either pay $258 for cancellation fee or upgrade to Economy Plus then cancel so I save $80 for my round-trip. I’m confused and this is my first time having an issue like this, and I never used Expedia protection plan before. I did cancel my hotel, but the flights are bugging me.

How do I use the protection plan? Can I upgrade, cancel, then submit a claim? They can refund for any reason for cancellation right?