Call Forwarding Not Reachable

I have talked to 4 different people today and this does NOT make sense.  There are 2 options for call forwarding.  The first one states - Call Forwarding Not Reachable.  Description states that IF service is interuppted, all phone calls will be forwarded to the number we put in place.  That is GREAT!  That is what we want.  There are times when internet is working, but phones are down and we don't realize it until a customer comes in our shop and says - why aren't you answering your phones?  All it does is ring and ring.  So, this option is exactly what we want. 

The next option is Call Fowarding Always.  We have NEVER had this set up.

Over the past few days - the personal cellphone that we have set up to recieve calls during the Call Forwarding not Reachable has been receiving calls during the day when our phones are working (we have 10 incoming lines).  Our receptionist is sitting at her desk, other lines are active but the phones aren't ringing and it goes to that cell phone. 

After talking to multiple people today, I was finally told that because I have that cell phone number under the Call Forwarding Not Reachable - it's eligible to receive calls at any time.

Does that make any sense given the descriptions that are provided???  Then why even have the second option that states Call Forwarding Always?

Anyone else experiencing this issue?  I turned the feature off (hoping to maybe restart it), then turned it back on.  We'll see if he starts receiving calls on his personal cellphone again.