Movie theater is asking me to give my phone number but I don't want to.

Recently I went to a multiplex theater and they're asking me to tell my phone number but I don't want to disclose my personal number so they tell me that without my number they can't print the tickets, last time I checked I read that the businesses can't force customers to share their numbers. I need to fight this, can you guide me where to start. Or should I directly involve department of govt regarding this?