blue20ae

When you pick up the phone and the incoming number is not one that you are familiar with, then do NOT say anything and wait for the other end to go first.  The powerdialer in call centres will try numbers one by one and wait for someone to answer then pass the call to an operator.  If you don't say anything, the power dialer will think the phone number is a fax (or not in use).  It will hang up and try the next number.  Some dialer will also remove the number from the retry list.

If you do get connected, tell (lie) them someone in your household work in a marketing company. Any legit marketing company will have to end the call immediately, and likely remove your number from the calling list.  If they still talk then they are crookes for sure, then you should hang up.