As I wrote, for me this was many years ago, but the issue we were having was that the single user and site/company ID (for submissions) had a 1:1 relationship. At that time, creating a new account would have ended up with a new number. I always assumed that enough phone calls could get it straightened out, but that it wouldn't necessarily be quick.
The times I got dragged into this were pretty much textbook "poor planning on your part..." situations with a healthy dose of "oh, are these the consequences of my actions?"