I actually used to work at Deerfield and associates for a very brief time, don't blame me I was desperate and naive. They're a very small telemarketing cold calling company out of Phoenix Arizona.
What I can tell you is they don't stop until they get you on the phone.
So pick up the phone and say
"Take me off your calling list"
Or
"Put me on your do not call list" and if they try to talk you into stuff still, say it again.

also please be nice, I know first hand how awful it is to be a telemarketer calling people you KNOW don't want to be contacted. Please please please be polite, and they'll be nice to you too. They work with an automated dialer and they just get a "beep" in their headset once you've picked up. It's not their fault, they're just trying to earn a living.
One of my friends who previously worked there as well said she got a call from the FCC and a message about an investigation, so definitely if they call you back after you say "take me off your calling list" or "put me on the do not call list" then report it to the FCC.
Also, if you've done business with any of the companies that they call for, like I sold $40 health books over the phone that were some on the doctor oz show I think, they're legally allowed to call you even if you're on the national do not call list. (Or at least that's what they told me)
So, I hope that that was helpful. I try to tell everyone how to deal with telemarketers since I was one and felt so awful about it. I hated working for Dearfield. My managers were awful, Vicki and Oliver, just overly saccharine and just. Awful.
Hope that helps.
Bring Deerfield down!