Referral Friend Missing Reward

I signed up for the Refer a Friend program in September and was accepted. Then, I referred a friend who started T-Mobile service and acknowledged my referral invitation. I then received a T-M email confirming the referral. The 45 day wait period ended this past week and I received an email link to my $50 MC but my friend has not received a similar email link. She spent most of the day on the 800 call with no success in finding out why/where her email is. Any suggestions?