The flight in question that I booked was actually LIN-LHR, and was billed in CAD.

At the time I was doing a "Reverse Ex-EU". I could get a ticket from Canada-LHR in CW and the prices was ~$6,000. However, if I bought a ticket Canada-LIN it was between $2500-2800 for the same dates, also in CW. Then I nested a LIN-LHR round trip into that. So I would fly to Milan, have lunch in the lounge and then fly back to LHR (again) as I had connected there on my way to LIN from YYC. Reverse the process going home, and I'd go through LHR twice in a morning.

I had the LIN-LHR flight billed in CAD as was easier to claim back on my expense account if everything was in my home currency. I also avoided a 2.5% forex fee on my credit card.

Apparently Chase allow you to do a chargeback for the difference. Rather than billing the airline, Chase covers the fluctuation. (This is an official process which the agents should be aware of). Give your cc company a call and ask them.

And my entire initial point was debunking a claim made by yourself that you could change currencies via BA’s website which you’d insinuated was an incorrect assertion...lol. Probably best that one re-reads a comment before correcting/disagreeing haha. I had already clearly stated that booking via other channels will indeed allow for a change in currency, which later on you’ve confirmed yourself that you booked it via a non-BA website channel! ;)

Of course it’ll bill in CAD on BA’s website if it’s an ex-Canada itinerary. No disputes about that. Please bring up an ex-Italy to Canada itinerary (non-Avios) on BA’s website and if it charges in CAD even for that (or indeed allows you to change it as per your wish), then I’d love to know what one has done to get it to do that. :)

BA's website does not support currency switches, many airlines do allow this. However you can call up and pay in a different currency for the Point of Sale, so the OP could have paid directly in USD or indeed CAD, rather than GBP. I think you have to pay the £10 service fee for that, but with some transactions that is a better deal anyway given what some cards charge (e.g. 2.99% on Amex).

However this is all a red herring, had the OP paid in USD or CAD or whatever then the refund would still be calculated according to the POS reference currrency and then translated to the original form of payment at the relevant IATA rate. And thus the arbitrage results. The only way I know around this is that if the refund is close to the original transaction, some credit card companies match up refunds and can spot if a difference is currency related, they then clear the refund down against the source transaction, either automatically or upon request.

This is correct. I've seen multiple reports on this.

In Hong Kong, I can call the bank to get back the difference. In particular, sometimes there is a foreign currency transaction fee of around 2% that the bank should pay you back but they normally don’t do proactively.

Amex does the same. You can just do a dispute online and click the appropriate boxes.

Or don't wait for BA to refund, just do a chargeback of the full amount when the flight has been cancelled / they have not refunded within 7 days on the basis the service won't be provided. My experience is that then there's no question of the current exchange rate.

I believe that if you use Curve you will get back the exact amount you paid in GBP, at least this is my experience with transactions of smaller amounts, but of course Curve comes with a fee-free limit unless you pay the subscription.

The airline has provided a full refund - the customer's bamk fees are not BA's issue
Contact the card company and it may choose to reimburse the fees

With the airline having agreed to a full refund and having paid the refund, there is nothing to dispute

Yes, this is why you need to dispute it before the refund arrives, when there still is something to dispute.

Chargebacks incur significant fees for merchants, plus much higher internal processing and admin costs. For many of us, this crosses a moral line - totally fine if BA has screwed up and it’s the easiest way to get a resolution, but as here they’ve agreed - and paid - a full refund without question or hesitation and have done nothing wrong, I personally don’t think it’s fair to screw them over for it.

In addition, in Europe chargebacks are only allowed (under Visa/MC rules) if an attempt has first been made to get a refund from a merchant, so your advice would not be permitted anyway (although I appreciate the OP is in the US, where rules differ in this respect).

US card issuers are free to require that a consumer make a good faith effort to recover disputed funds from the merchant vendor. Some do, some say they do, and some don't. The exceptions are bankruptcy where it is recognized that it is futile to try to recover and certain items such as fees imposed by the card issuer itself.

OT (apologies) but worth noting that Curve now charge a fee for currency transactions that take place at the weekends:

Source: https://support.imaginecurve.com/hc/...-money-abroad-

On the other hand, BA is supposed to refund within 7 days and frequently flouts this requirement. And of course with no website option and long phone waits (not so relevant for silver / gold members) getting a refund can be frustrating. I don't think its fair for the OP to have to take on exchange rate risk for as long as is convenient for BA, and once it's day 8 after seeking a refund I think BA is fair game.