Update, Eneba reached out to me and processed a refund already. I actually ended up buying another card as well and the code worked, so in total I was 2 for 3 and refunded for the bad code. Surprised that they were able to process the refund so quickly, so props to them for that at least.
Just adding to the warnings, I bought two codes at once and was able to redeem one to my account with no issues, but the second code showed up as "already redeemed". Submitted a ticket with Eneba and am hoping the issue will be resolved, otherwise I will escalate to PayPal as well. So definitely...