I think your problem is that you used a credit card as a shim. You should have used a debit card.
Sorry - couldn't resist. No use in trying to correct a fret buzz issue occurring around the 12th fret by adjusting the truss rod. From the 12th on up, the problem is that the bridge isn't high enough for the strings to stay clear of the frets. However, if there is a ski jump you may have to raise the saddles too high for your liking.
We might be able to help if you can provide some measurements. What is the amount of relief in the neck? What is the height of the strings from the 12th fret?