Try DACO (Departamento de Asuntos del Consumidor / Consumer affairs department) http://www.gobierno.pr/DACO/Inicio/ (broken link)
Or the Ombudsman (
www.ombudsman.com)
As far as I remember, DACO deals with businesses while the Ombudsman takes complaints against government agencies. Being that the telephone company is no longer government owned, I would think that DACO would be the place to call.