Amazon does have some strange issues with GC purchases. In March this year, I was unable to see the credit card options for buying Amazon GC. I had purchased Amazon GC the previous month using CC for around 20000. When I tried this month, I was able to use my Amex MRCC without any issue. So their must be some caps... Gyftr isn't a good option for Amazon GC any more, as they are charging a processing fee... Card specific portals may be of limited help. I want to use my MRCC usually for Amazon GC. Reward Multiplier no longer has Amazon... Hope Amazon would stop being silly...