I have a BCM 400 with 7316E sets. Each is assigned a DID/target line with 2 appearances. When the first is busy a 2nd incoming call goes to voice mail instead of rolling to the 2nd appearance. I'm being told there is no way around this. Why have 2 appearances if the 2nd one never does anything?? Is there a way to ring on the 2nd appearance if the 1st is busy then go to voice mail if not answered??