On the other hand, I emailed bj's and lied about my connection to their customer. Their response is,
"Hi ,
Thank you for contacting BJ's Member Care.
We really do appreciate your honesty. Your cousin would be required to return the remaining gift cards unless they are wanting to keep the gift cards and we can charge for them. If they are wanting to return the gift card, this will be a bit of a process. Please provide me with the order number and how many gift cards that the Member had received. Once you provide me with that information, I will forward it to our Orders Team who will send someone out to pick them up. Thank you so much again for you honesty.
We appreciate your business, and look forward to seeing you soon!"
So, this conflicts with the law/recommendation. Up to you what to ultimately do, but since we are not actually related there's no way in the world they can find you through me. Well, except maybe chocolate. I might be coerced with lots and lots of really good chocolate.
Anyway, kidding aside, zero judgment. If you want the contact information, I can PM you.