Many phone companies are now recording robocalls. Some companies do not use this technology at all, while others use it very lightly. So when a phone call comes in, it will record the numbers, date and time of the call, and then it will send the recording to you. You can then use the information you receive to report the caller to the FCC. If you want to block a telemarketer from ever calling you again, then you should use a service like robocalls blocker to get rid of the annoying calls.