One time at Walgreens I had bought a bunch of items that had cash back by mail rebates on them. I also bought some other items in the same purchase.
One of the other items rang up the wrong price, so I had to go get a refund on it and they circled that item on the receipt. Then I sent in the receipt with my rebate forms filled out and then weeks later I got a letter from Walgreens saying that they were not going to give me any of the rebates because the item that I had purchased that had rung up the wrong price had been circled on the receipt and refund written to it.
That was the last time I ever tried to do any of that rebate crap from Walgreens, and they lost alot of business that I would have given them because I was very pissed off that they didn't honor my rebates that I sent in. Also, I stopped going there because every time I would go there, just as soon as I would enter the door, they would go over the loudspeaker and announce to the whole store: "Security, Scan And Record All Areas Please!" and I would be the only customer in the store many times when this would happen.