I have a BT landline with BT Broadband and I recently signed up for BT Mobile as well. I am sure I remember reading in the advertising leaflet which persuaded me to change my mobile to BT, that calls from my home phone to my mobile would be free of charge but I see that my "recent usage" includes chargeable calls from my home to my mobile.
Live chat to the Billing team produced only a succession of conflicting statements which proved they were incapable of understanding my problem. Can anybody here shed any light on this? Have I remembered the leaflet wrongly (unfortunately I don't still have it) or misunderstood it?
They are not free. You may be getting confused with BT SmartTalk which allows you to make calls from your mobile which are included as part of your landline package, which would include some free calls.