Ok, The shipment arrived today, but had only 8 boxes not 12. I contacted the seller, a vendor for Walmart, and was told they would ship the rest. Later in the day I received an email from Walmart customer care and the vendor’s customer care confirming this.
I suspect a mistake was made on the listing because it now shows out of stock.
I received my order yesterday (shipping was delayed) and just like yourself my order only contained 8 packs. I have contacted the seller and am hopeful that they know about this issue now and will drop the 4 packs in the mail for me.
Came home to the remaining 4 packs of blades waiting for me on the porch. I've gotta hand it to the seller, they made good on their word and advertised deal. This will keep me flush with injector blades for quite a while.
Thanks to @Fuzzy for making this thread and alerting me to this offer. Simply too good to pass up!