What are some things to tell to telemarketers to ensure they'll never bother you again?

Persistent bastards aren't they? You know what I used to do before cell phones came on the market? I would unplug the phone Jack and whoever was trying call it would ring on their end but on my end it would not ring making whoever was calling me think that I was not there. The only thing I can suggest you do is get your number changed to a private number, obviously someone gave out your number. I know those telemarketer are a real pain in the ***. especially when they call you at 2 AM with some ridiculous BS and If My Sleep is disturbed for some retarded reason I can become the Devil himself and be in a nasty mood