Why can't I buy with a store credit without adding a credit card?

[edmg]

So, for some reason I got a $14 CAD store credit. I can't use it, because for some reason when I use my Amex card to pay, the prices are always in US dollars. So I deleted the Amex card and now the prices are in Canadian Dollars. But when I go to buy an app which is less than $14, it says I have to add a credit card to buy the app even though the store credit is more than the cost of the app.

Is there anything that can be done about this?

[Anonymous]

That's just the way they do it.
Add a payment method, buy your app, then remove the payment method.

[edmg]

You don't get it.

If I add my Canadian Amex card, the prices switch to US dollars and, lo, I can no longer use the store credit because it's in Canadian dollars. Even though I'm in Canada using a Canadian credit card and the price of the thing I want to buy is less than the store credit.

[Anonymous]

Do you have Paypal? That would fix the problem.
You could also open a support ticket. I was given a store credit in US dollars once, and I am in Australia. They fixed it via support.