Click this link in your ppc.
http://calltones.sprintpcs.com:8080/...BZLAIzZBLZvNYJ
Note that the id, i believe, identifies your phone to sprint. A user on ppc6700 posted this link and I believe it takes you to his profile. He has a password prompt before allowing purchases.
See if you can use it to get into the site for your own phone.