Texaspup there IS a way after they do first call. I bought a Panasonic phone (has 3 additional phones with it) I'm sure there are other phones that do this....I get a call from scammer (if unknown I go to this site to determine if scam), then I can block number, the nice thing about this phone is I can also mute first ring (yes mutes all first rings even for calls you want but no big deal, phones ring a few times anyhow)....so when a scammer calls back after I've blocked their number, it mutes the first ring, then blocks their number so I don't even know they've called, never hear ring, blocked. Heaven. But unfortunately you have to hear & get the first time they call, but once blocked, all good. This phone allows up to 250 blocked numbers. When full, I just start over.
Caller says they are part of a program to lower interest rates on credit cards. I got to a human and asked that my number be removed from call list. The person ignored my request and kept on with the spiel. I said over and over "do not call this number" until the person hung up. My understanding is if a company is told not to call anymore, they can't. I want something done about this.
The call you received was from scammers who want only to steal your credit card number and other personal data (as much as they can trick people into giving out). Criminals like this aren't going to honor your request not to call any more.
You want something done, get it done. Obtain business names and locations. Sue for TCPA violations. File complaints with the FTC and attorneys general. The crooks lack incentive to quit until they feel heat under their tails.