For a variety of reasons, a chargeback may be declined. You must produce a compelling statement stating that you did not make the charges and that you need your money returned whenever you file a chargeback. Typically, the fees will be distinct from what you normally spend your money on.
You may also be required to establish that the charges were completed in a state or region to which you did not travel. The bank may reject your chargeback if you don't have enough evidence. Merchants may also show the bank proof that the charge was made by you.