I'm not sure where you got your phone, but if you bought it an Apple Store, you have 30 days to return it, not 14.
Not sure how that works with the carrier contracts, though - at least ATT changed theirs to 14 days about this time last year. Exchange may be a different story, but will the carrier give you your eligibility back & cancel the contract even if Apple (if you bought it through Apple) takes the phone back?