Darrel999: What company are they calling from?
Are you sure it's the same company you've had a previous business relationship? The FTC allows them to telemarket you 18 months after closing accounts with them.
I would recommend recording the calls, and getting their address. I've sent letters certified mail return receipt requested (CMRRR) requesting no more calls to be made for telemarketing services from current creditors.
However, there are some scam callers that will ask you several questions---they want to lower your interest rate. They want to know what credit card company you bank with. They want to know the interest rate, and want to know the card number and expiration. They're supposedly calling from your bank. Those are scams, and you'll probably not get any information from them.