VMCAS' GPA and my GPA were different because (I believe) I took my GPA straight off of my transcript, and VMCAS included my "other Institution" (study abroad) classes in it. I can't imagine it's an uncommon thing, and I've since been verified. So personally I don't think you should worry about it.
That just sucks. I'm sorry, and I know that must feel frustrating and disappointing. Still...try to keep your head up. Mistakes happen, but beating yourself up will not change Illinois' decision, so show yourself a little more kindness! The other side of 1/3 is 2/3, right?
I agree with the comments above, they're probably completely swamped. I actually had some earlier confusion with inputting certain courses. I spoke with the VMCAS help desk and once we finally figured it out, they said they were going to put a note in my file so that the confusion didn't happen again during my verification process. So that was probably a factor in my quick verification. Just a thought!