How do you contact constellation customer service? Customers at Constellation can contact 866-604-1859 to speak with service representatives. The company also features an online contact form for questions or comments. Pay online: Customers can pay by debit or credit card through their online accounts. Pay by phone: The company’s automated payment system is available at 1-800-785-4373.How do i pay my constellation energy bill? Constellation Energy provides the following methods for bill payment: Pay online: Customers can pay by debit or credit card through their online accounts. Pay by phone: The company’s automated payment system is available at 1-800-785-4373.What is my constellation? My Constellation is a paperless billing system that allows customers 24/7 access to their Constellation accounts. Through My Constellation, you can view up past invoices, set up email account alerts and receive e-statements. Customers with a My Constellation account can pay easily online without the hassle of paper bills, stamps or checks.How do i make an appointment with constellation? You’ll receive an email confirming your appointment, and a certified Constellation technician, electrician or plumber will arrive at the time and date you select. You can also contact Constellation through Facebook and Twitter. Our social media accounts are monitored from 9 am to 4 pm CST Monday through Friday.