Caller: "Power Save" ??

Called back - automatic answering says "Welcome to Power Saver" to talk about offers on electricity and gas. Gives you the option to press a number to speak with an operator otherwise press another number to be taken off their calling list. I definitely didn't sign up to any list however I'm certainly not pressing any numbers.

let ring for a bit. hung up when i answered

called back the number is not in service