[Kushan]

As far as I understand it, there's like a database of which modems are allowed on an account. A regular agent can try to add a modem onto an account, but if it's not listed in the other database, the system refuses to let them. There is a department that can add them but they're not customer facing, which is why it's so hard (albeit not impossible) to get an old modem put back on your account.