no answer when I picked up

I keep getting the same number calling but I always miss it cause I'm so busy at times.. So when I call back I get this Low weird Music. Wth

Called at 4:40 pm when I was out. No idea if No mo blocked it or not.

called twice in a row claiming they are Edison

A young Hispanic woman, obviously in a call center, asked for me by name. I asked who was calling and she gave me the name of some solar company. I told her we had no need for their services and asked her to remove the number from the list. It's the second call. I only answered this time because I was curious. Now I am blocking them.