The phone plays an interesting role in The Chocolate War. Telephones are usually symbols of communication. That makes sense, right? One of the main ways we communicate is by talking on the phone. However, in this book the telephone's symbolic meaning becomes the total opposite of what it usually is.
We see this when Jerry takes a risk and calls Ellen Barrett. He's been checking her out for a while at the bus stop and has finally got up the nerve to call her. This sad attempt to communicate totally falls apart, though. He just can't make her understand what he's trying to tell her. She thinks it's a prank. And so the phone, a symbol of communication, becomes a symbol of miscommunication, and the loneliness that goes along with it.
The phone becomes a much more sinister object later on when The Vigils begin stalking Jerry. Through the phone, The Vigils are able to intimidate Jerry even in his own home. It doesn't scare them in the slightest when Jerry's dad answers. We're guessing this is exactly what they want. At this point in the book, it seems like the phone becomes a symbol of The Vigils' powers of intimidation. It kind of reminds us of the movie Scream. (OK, even The Vigils aren't quite that messed up.)