I had this same issue a couple months ago. Couldn't buy any gift cards, no matter what I did or how many credit cards I used. I contacted them through chat, they asked all the usual questions, and eventually told me they would send my complaint to their "elevated team". After a week, they emailed me and said they fixed the issue. The email said if I had any issues, to contact them: "If you have any additional questions or concerns, please feel free to reply to this email (consumercare@aarp.org) or telephone a member of the Consumer Care Ombudsman team at (877) 634-8313." But I haven't had any issues since.