AMEX duplicate charges occurring with users with same last 4 digits.

Hello - I have had many issues with AMEX, but the main one that has been consistent, is if I have 2 AMEX users with the same last 4 digits, when I link the cards, their transactions show up on both users credit card activity. I have contacted support so many times and each time, they have me send all the necessary files from AMEX and Financial Edge, but nothing ever gets done about it. It's very frustrating, and so far, my only solution is to click ignore on the charges that aren't correct. Is anyone else experiencing this issue? Have you found any resolution?