Hi.

You could just go ahead and cancel that order, If they said 3-5 day availability, and now change this to "30 days, may be less", this obviously makes your decision to order the disk from them invalid. I am not sure about american laws about this, but according to german law, you can just quit a contract (each order is a contract), if your contractor changes the conditions to your disadvantage.
However, I would only cancel that order after confirming that harddrive.com really has them available within 6-13 days.

cu,
sven

proud MkII owner (12GB blue/green/smoked, was #080000113 is #090001010)