I've used Headshot Ammo in the past, and while I've had consistency issues with some rounds being hard and some soft, they all fire just fine. I tested with my Kronos when I first got it last month, it fired the Headshot Ammo rounds as well as the Nerf Rival rounds. There is the occasional dud that might not go as far, and I think this specifically has to do with their densities. I got my batch last year, so I don't know if anything has drastically changed since then.
Those do strike me as odd, however. While I do not remember what the packaging looked like, I specifically remember getting the rounds in a little mesh bag with a carabiner clip. By the looks of things, the ones that OOD handles now seems to be the same. Yours came in this plastic bag, which may be a sign that they came from a different re-seller. The bag does say DynaMax on it, them being the sole seller of Headshot Ammo on Amazon. Just check that these do indeed have the "HS" embossed into the side of the round where the "N" should be.
Just checked the order we placed for the Headshot Ammo rounds last year, and the price has went down significantly, from $21.95 then to $12.85 now, so that's something to consider. I've really never had experience with getting fakes or items with deceptively misleading photos on Amazon, but I think you should probably contact the seller directly in this case. You should also probably try OOD's etsy next time, I wouldn't imagine that they would sell you something so crummy.