Don't do this
I would never think about signing up for a credit card with an annual fee and then canceling. $59 for 15 credits is a for good deal. You should just pay the $59 you cheapskate lol. Where can you get a roundtrip ticket for $59?
I signed up for the Delta Credit Card and paid the $100 beyond the first year just to give Delta revenue. I would feel bad canceling right away.
Just pay the $59 and cancel in a year if you don't like the card.