How did you do it? I had the worst time in May. I gifted myself and received my gift 2 days before the Prime expired. when I clicked on it the only option was to add the $72 to my account as a gift card, so I did. I called
Amazon and the rep told me she thought that when the Prime membership expired, it would use the $72 to renew, it didn't and you can't use a gift card to pay Prime which is ridiculous. The rep called me on her day off, had me renew the Prime using my credit card, waited until she saw the transaction, credited my credit card but left the Prime for the year. I asked her about the $72 that I had in my gift card account for Amazon and she said that I could keep it! she called me twice on her day off, best customer service I have ever had.
Worked out well for me as I got Prime free for year but I still don't know what I did wrong when trying to use my Prime "gift" to myself.