Here is a quote from the website:
Sold Out! ? We're sorry, but we've completely sold out of our Jorgensen Clamp inventory. What was normally a five year supply of clamps sold out in less than one hour. This was a one time offer from Jorgensen and they have no more inventory available to us at this special price. If they did, we'd be more than happy to sell it!
We certainly understand your disappointment and if it's any consolation, we'd like to offer you a 10% discount on any purchases over $50* that you make in the remainder of this month.
Our stores also carried the clamps, but please call your local store before you make the trip. It's possible the stores experienced the same clamp sell-out.