UA's "liability" is only with respect to the airfare. UA does not cover consequential damages, that is what the trip insurance is for. And it appears you were not the direct ticket purchaser.

As your travel was a "trip in vain", any fees or airfare you paid to UA should be 100% refunded -- make sure to refer to "trip in vain". UA will also reschedule the flights at no additional fee in the future instead.

UA may additionally provide an apology certificate of $100 or a bit more for the "inconvenience" depending on the cabin of the air travel and airline status.

Working with your TA is key for rescheduling and getting the bulk of the refunds.

Suspect all this is less than you hoped but that is the system we have in the USA (and all USA based airlines). Things in the EU are quite different.