UK Dopers, can you still buy gift cards with your Amazon credit?

Another forum I visit does competitions occasioally. I win more than my fair share of them, and the prize is always Amazon gift credit. For over a year I’ve been skimming off it by buying myself gift cards to Greggs, Primark and other such places I buy from anyway. Now it;s not letting me, but I’m unsure if this is a global change or if they’re stopping me personally as I buy too many 3rd party gify cards.

Could a UK doper with Amazon credit try buying a 3rd party gift card, (eg Greggs) and see if at the payment screen it allows you to select gift balance to pay?