OXO how to stop trnsfrd xtrnl call to rm extnsn to be crgd

[LaciPerth]

How can we stop external calls picked up by operator and transferred to a room to be charged to that room phone extension. This happens regardless of the transferring extension. Other software used is Phonecontroll and Opera. "Assign Auth. for Count charge" is not ticked, we tried to restart Phonecontroll no change..