Additional general consideration about chargebacks:
- A succesful chargeback can be reversed at a later stage if the vendor manage to provide evidence that the claim was incorrect to start with.
- If Amex was used, it tends to side with the customer more then the vendor in the majority of the cases, unless the vendor can provide unconfutable evidence of being in the right (written T&C, video or audio recording, etc).

Also, in making a Chargeback claim, you need to confirm that you tried to resolve the issue with the vendor, and if one stated to have done so, and the counter part prove that you did not (e.g. like it should be in this case where refunds are standard procedures in case re-routing is not suitable), then it would simply fail.