Originally Posted by corporate-wage-slave

Personally I suggest you beg BA to give you a Future Travel Voucher, this may take a while. Or alternatively a partial refund. They may well do neither, but the rules are that Amex have to do this for you, BA will not deal with you if you used a travel agency since it is under their contract. This may actually help, since Amex has a bit more clout that any individual traveller. This could take a lot of time. So I would suggest you book flights which do not stop in Europe (or Brazil). IST is in Europe and that is allowed, Qatar to USA is the other option. The waiver referred to isn't for casual visits, very few have been granted, it's a non trivial process, whereas buying a direct flight is essentially allowed. You may be allowed to transfer via Canada, but I wouldn't add any unnecessary complexities if you can avoid it.