UPDATE:
Swappa refunded my the $25 fee on Friday after I sent an email. Great customer service!
I also got an email this afternoon from PayPal that the seller received the phone and PayPal refunded my the money. I should be back on my Visa within a couple of days.
So thankful it worked out. Lesson learned.
Just curious. How much did you pay for the used phone. I'm sure the price couldn't have been reduced enough to justify buying used this close to release day. Or if it was reduced a lot, that should've been a red flag. I would just buy a new one instead of saying this was a sign to stick with iPhone. This was a sign to be more careful.