I got no experience with them, but I find that many sites, probably the one in question included, has a check to remove if you want the item shipped to another address other than the billing address. I bet you failed to uncheck that box which would have opened a new window for ship to.
I have to ask what will be so bad if they ship the item to your work? You will be there, right?
So you emailed two days ago and you are worried you have no response! By my calendar, there is a Saturday and now Sunday in those 2 days. I doubt they are open on those days!