From what they told me when I called to retrieve my code (lost in flashing), once the system acknowledges that you're eligible for a referral code, the system automatically generates one for you and sends it out to your phone via text.
Customer Service can retrieve it once the system puts it out. They have no way of retrieving or generating one for you if the system doesn't initially send out a code to you.
That's what they told me.
What I understood was they do not want endless calls of "what is my code?" unless the system already sent one out to you. Good luck.