Could be a store by store issue then capt. apathy and that is a risk one avoids when getting the part from one source.
I made the error of buying some RAM at a Best Buy once (yes, it was the Samsung chips and I was in panic mode to get a new server online). They gave me the wrong parts and when I went back they told me they could not take them back and I would have to buy new ones. I wrote a letter to Best Buy corporate and they finally gave me credit, but that is just too much to go through over a simple error.