Connections

Reviewed.

The film's theatrical trailer is featured.

the killer figures out that the main character reached him by dialing the wrong number

Very similar storyline of a young teen girl in love with an older man/killer mainly through phone conversations.

Two young girls making prank phone calls and calling a killer.

Batman mentioned

The Ending is an homenage.

The girls say they feel like Magnum PI after they track down a phone number.