That may be one of the circumstances where you will need to be patient, perhaps raising a CEDR case if you can articulate this as BA acting unfairly. The process is that the refund has to be returned to BA and for BA to be able to located the refunded sums, bearing in mind banks tend to be incredibly vague as to why they have refunded a sum and perhaps not linked it to the original payment from BA to bank. Once that has been established, and that the bank is refusing the transfer, then BA will eventually consider alternative payment routes, but it has to be after the transfer route is established to be non viable. So this will take weeks. If you are totally certain that BA has received back the fund from Amex, then if you don't appear to be making process you could send a PM to the BA Refund Helper account here on FT.