You'll be fine mate. Places like that are usualy a little slow. Yearone, Tonysparts and Mancini are VERY quick. Tonys parts were a little slow with one of my first orders but 10 orders later they have been nothing but goodness!
Send an email with you order number, if you don't have one find the parts, the part #'s, the date the order was purchased and ask them to advise status of order ASAP.
Always works.
I have never used Jacks but have order HEAPS of parts from the states and do know what I'm talking about.
I'd like to hear how this turns out for my own future reference so please keep us informed.
All the best and I hope it's nothing more than a little laziness.
Cheers,
Carl