Phone connections says not connected to network

Am ready to alreadybquit Xfinity. Phone message repeatedly is 'not connected to a network' so no calls can be made but texts can.

My account says no balance but just received an email claiming my account is 'overdue.' 4 hours on the phone with a series of  'expert' customer service reps has me thinking people woth no knowledge are manning the phones. 

Promised great service and instead this? Am a report in northeast on consumer issues. This week's  column is going o be great