[CentOS] network automatically connecting on boot after new service installation

2 weeks ago, i had my internet service changed from copper DSL to fiber DSL.

now, every time i reboot, internet connection is automatically connecting on boot.

before last update to 6.6, i could configure connection, now i can not bring up configuration window to disable auto connect.

because of uneasy feelings about leaving computer up when i leave home, i disconnect 'bell line' so that when i am gone and have a mains failure and ups shuts down, i will not have internet connected when mains restore.

also makes for uneasy feeling when retiring for night. :-)

what do i have to do to change this?

any and all replies / suggestions greatly appreciated. tia.