The phone ID said Customer Service. No sound in background. After 20 seconds I heard a click. After 35 more seconds, the line gave a busy signal. 30 seconds after I hung up, my LED said "Line in use." I called myself successfully, so the line stated it was in use but I could also use my line. 15 seconds after I hung up from calling myself, the LED said "Line in use" again. I called the caller back and heard Hello. None of our representatives are available right now. (There was another sentence.) If you received this call by error, press 1 now to be put on a no call list. I hung up. We receive this type of call almost every day but the caller's number is different. I do not/not have a shared phone line. I presume someone is using our "unlimited long distance" phone line and its activated once we answer the phone.