Caller: Pretending to be an energy broker

This company, pretending to be an energy broker, asks who your energy provider is and caims they can get you a better deal or possibly you have paid too much. When questioned how they got my number they claimed third party and they are trying to help. They wanted personal information like account numbers and address, name, date of birth and banking details. I didn't give them any and she got very angry and hung up. Call back and says number not in service.

Guy said he's going to punch my head in for telling him to f off and stop calling