I have been trying to understand this issue for weeks. I even have a spreadsheet I built and fill it in each day.

Each day I check it and there has always been $5,300-$29,000 discrepancy between my available credit per Amex and my Credit Line minus my Outstanding Balance.

Some of the discrepancy is pending charges, and I have been watching that and feeding it back. But pending charges are by far less than half of the discrepancy.

And it doesn't get fixed in any rational way I can explain. It'll ramp up and down based on events I can't see.

Also, for days, my available credit shows ZERO, but they continue to accept charges on the card.

I'd love a good explanation of this. I have called around 8 times asking. So far no one has been able to explain it, and only about 2 of 8 times have they been smart enough to make the appropriate adjustment to fix it.