The call is from Express Scripts they are good I've been using them for years it's a legitimate call no need to block them it may help you out somewhere down the road.
Express scripts helps no one but themselves and if you believe otherwise you are deluded. I guess I would have to wonder why you would take the time to look up a number on the internet when you claim you already knew who it was and why they called. Just doesn't seem logical to me. Maybe you are one of the scammers trying to convince people to answer this call and give up all their information and money?