Well here's what happened:
I called MS store and talked to a nice American girl. She told me that we could cancel my order from Digital River, and then i could buy the student Pro version from her right there and then. To be sure, she called over to Digital River to make sure they could cancel and refund my order. It turns out they can't do that (for no good reason), and that there's not much more that she can do from her end, so she would transfer me to Digital River tech support to help figure out my downloading problem.
Sooooo I then got transferred to India. I questioned the guy as to why they do not have the professional edition on their website, because if I would have known that it was offered I would just have bought it from MS store. After some convincing, he agreed to upgrade my edition to professional, which is good. However, he didn't know why my download manager wasn't working, and told me just to wait a couple days just to see if it clears up.
I'll probably wait until tomorrow, and then if it doesn't get fixed I'll take my computer to my schools network help desk (I emailed them and they offered to do it for me). The problems not fixed, but at least I got to change to professional, which is good.
One off topic thing that I noticed is that these off-shore tech help people DO NOT pause for one second to let you speak. This guy was talking and talking and I tried to interrupt him a few times but he just talked over me...didn't even pause. Same thing happened the other day when I called MS tech support....absolutely ridiculous. The difference between the MS girl and the DR tech support was like night and day.
Anyways, thanks for the help. I'm sure I'll get this figured out eventually.