[mothered]

I paid with a gift voucher that I had purchased.
I check their terms, if you paid solely with a voucher or giftcard (I paid solely with voucher) your account balance is topped up with the amount that is refundable.

Okay, now It makes sense.

Given you've paid with a gift voucher/card, that's what I was (and still am) referring to In my earlier post as per below:

tell ASOS you no longer have access to the GC and would like the funds debited to your CC.