I am not a movistar employeee, but i am trying to anser your question.
I guess you are a movistar Public Switch Telephone Network suscriber. If so, it is very easy solving your problem.
Write movistar a letter to the folowing adress
Movistar (Telefónica de España, S.A.U. )
Referencia: DATOS
Apartado de correos 46.155
28080 Madrid ( Madrid )
As you can see reading the folowing document
https://www.movistar.es/rpmm/estaticos/residencial/fijo/lineas-individuales/contratos/contrato-abonogeneral-serviciotelefonicofijo.pdf
Look for "PROTECCIÓN DE LOS DATOS PERSONALES" ( look for that exact words), and you will find you can change your personal data writing a letter to that adress.
Any question, write another post
Best regards