Is this that you didn't recieve a printed Certificate or that it hasn't registered in your UserCentre Account.
Possibly me being old but back in the old days you used to recieve a printed certificate in the post, which no longer get at all. Instead you print it out yourself if bothered once attached to your UC account.
If email addresses are the same and hasn't shown up then would contact account services, they will likely want your email address confirmation, along with a screenshot of your PearsonVUE showing you passed the course.