Retiree here from sales;
My wife's actual expendatures were overstated by $4,000 last year, and we knew this couldn't be the case. Our very thorough investigation showed that Express Scripts had charged us fully for a number of AZ products over the last year and a half. We did a written inventory, collected copies of just about everything possible, and faxed all the results to Express Scripts. They admitted to us that they had mistakenly charged us (fully) for the AZ products that should have been free....and it was obvious that this had been the case for just about all AZ products dispensed throughout the company retirees.
Express Scripts told us that the situation had now been "elevated" to the powers that be. I suggest that you do as we did and document your situation.
I'm also a member of the AZ Retiree Organization, and have reported all this to them. They have quite a few members reporting the same situation.
I will keep this site posted on further developments, and suggest that you and any other retiree having the same problem do the same. I'm pretty sure, having spent half a lifetime with AZ, that we are on our own here, and somebody, somewhere, knows all about this and is/was profiting royally.