They donu2019t disconnect the telemarketeru2019s phone number. What youu2019re seeing is callerID spoofing. The telemarketer sends a spoofed number as u201citsu201d number. If the number is disconnected, or has never been assigned, that has nothing to do with it.Why do they allow telemarketers to send callerIDs down the line, thatu2019s the real question. Their telco knows their number, so the equipment should just ignore the number being sent, and identify the call with its real number. But theyu2019d lose money doing that, and money rules.