Why Apple, calling from SMS is the first number?

Because that priority of the secondary card is set.

The display number of Apple's mobile phone can be changed: insert the SIM card, turn it on, click Settings in the main interface, and enter the system settings menu. Click the cellular network option in the system setup menu, and select the number to be set as the primary/secondary card in the cellular phone number. Select major number/minor number in the secondary setting menu, and then exit.