contract negatively affecting my score and does not belong to me

I DID USE MTN 2 YEARS BACK. ALL OF A SUDDEN I SEE THEY APPEAR ON MY CREDIT PROFILE (MY CREDIT CHECK) BADLY AFFECTING MY SCORE BECAUSE APPARENTLY I HAVE A CONTRACT THAT STARTED LAST YEAR.. I HAVE NO IDEA WHO MADE THAT CONTRACT, I RECENTLY CALLED THE NUMBER THEY WERE ALREADY ALLOCATED TO SOMEOME ELSE. THIS IS TOTALLY UNACCEPTABLE... WENT AND VISITED A BRANCH, THEY'RE ALSO NOT SO HELPFUL.