Tried to file my taxes, but it did not go through because it was a duplicate ssn, what do I do if someone I don't know used my ssn to file taxes? How do i get my refund?

I tried to efile, I put in all my correct information.  The transaction was rejected because someone else used my ssn to file.  I don't know what to do,.


This is my first time filing taxes, so I should not have a record for the year I tried to file for or the year before.