Pro Sites not working for me ...

1.
I have 3 Levels:
FREE-
a. Music Fan: 10 MB $ Free

PREMIUM-
b. Music Lover: 100 MB $5, $15, $50
c. Music Writer: 1 GB $10, $30, $100

2.
When an account gets created by a USER, it should allow him to choose Free or Premium Levels (no Free Trials), but it doesn't allow. It creates an account for the User and also doesn't assign the new site to the user. User gets these messages:

a.
Sorry, but you do not have permission to upgrade this site. Only the site administrator can upgrade their site.

b.
« Choose a different site

Please help.
Cesar