What does servicemaster do? ServiceMaster strives to be the leading provider of essential services through empowered people, world-class customer service and convenient access. Whether you’re a recent graduate or an experienced professional, a career with ServiceMaster will give you opportunities for professional development, advancement and benefits.Is there a customer service phone number? AT&T Customer Service Phone Number 1-800-288-2747. AT&T is a communications giant that is the largest provider of mobile phone service and home phone service.What is a service master? Service Master is the most complete service management tool for service companies, for easy and rapid navigation with detailed controls to meet the demands of the most challenging service companies. The most complete field service management solution.