Cancelled w kiwi, can i keep airline tickets?

Yes, I commited the worst mistake: booking with Kiwi.com. I had to book a return ticket to Sweden in a hurry on my way to Argentina because the airline wouldn’t let my girlfriend board the plane (allegedly the rules to get into the country). So I bought with Kiwi but then I cancelled because the trip had a stopover in US where is difficult for me to get a transit visa. I didn’t read correctly, and thought they would charge me 10 USD as a cancellation fee when in fact that was all they were going to return to me from the total amount (2900 USD). Cancelled yesterday, and when I realised I called them but apparently there was no rollback (Kiwi’s Saver fare rules). I checked in the airline’s page (Delta airlines) and the reservation is still there, it wasn’t cancelled. At least I would like to use the trip for my girlfriend to go back to sweden (She can get an ESTA, I can’t). I already added the trip to my account in the Delta page, is there anything you guys think I should do? I tried calling them but they won’t pick up