My own attitude is that time spent talking to me is time they aren’t spending making a sale, so getting off the phone is the nicest thing I can do for them under the highly constrained circumstances. So as soon as I recognize them as telemarketers, I politely say “Sorry, but I’m really not interested; have a good day” and hang up, without waiting for them to do anything in particular.
My own attitude is that time spent talking to me is time they aren’t spending making a sale, so getting off the phone is the nicest thing I can do for them under the highly constrained circumstances. So as soon as I recognize them as telemarketers, I politely say “Sorry, but I’m really not interested; have a good day” and hang up, without waiting for them to do anything in particular.