My son wanted a year long membership on Runescape for Christmas. Apparently there are extras you can get with a membership.

I shopped around for a while, but could only find $25 gift cards, so I bought 4 so he could get the $89 annual package.
Yesterday my son logged on to try to redeem the cards, and it turns out, you can’t. That is, you can’t redeem multiple cards for a single purchase. Buried in a FAQ that I spent 15 minutes looking for, only because I knew it was there, was this message:
Can I use pre-paid game cards for a Premier Club package?
Game cards can only be redeemed for the packages available on the
game card section of the website, which includes our standard membership.
It isn’t possible to upgrade from a standard membership to Premier Club.
I purchased the gift cards at a local retailer, and NO WHERE ON THE CARD DOES IT MENTION THIS LIMITATION. I have to think there are borderline ethics involved here.
Currently we are waiting for a response from customer support. What are the odds of a favorable result? We will see.