sim card activation not working

I am using a shared family plan for my phone and my sim card broke, so I went to an xfinity store to get it replaced.  They replaced it and said I should be able to activate it on the app. I tried to but when I click on Activated Mobile Device -> Start activation, it gives the error "It looks like your account is missing a verified contact."  The employee then said that my mother would need to activate it on her device since she owns the primary account for the family plan.  But when I contacted my mother and she tried to do it, the same error came up.  How can I fix this situation and activate my new sim card?