g-g, I've noticed your username on a few posts I've followed, and you have my sympathies.
I've been in the IT industry well over 10 years, and I have to say it pretty much disgusts me sometimes.
As a consumer I have had two unpleasant experiences trying to order new PC's from 'reputable' online retailers (MESH and Carrera). Surely this can't just be bad luck! The prices may have been competitve but the service was terrible, bordering on rude at times.
I have now resorted to building my own PC again, and although it cost me more it gave me peace of mind knowing the parts I had bought are quality components and if anything goes wrong it's my own fault!
In your case I would suggest, even though it may cost a little more, to go to your local PC World or other large retailer. The extra money you may end up spending at least gives you the knowledge that if it goes wrong you can physically take it back, dump it on the counter and get something done about it.
As for the external storage you ordered, I'm always wary when an online store only has 1 in stock. It's impossible to know whether they have a true real time stock monitoring system, so there's always a chance that the stock you think you are ordering has already been snapped up by someone else.
I hope your future purchase go more smoothly!