If the name "Emergency Call" is shown on the phone display while making a call, the callee extensions is probably saved in the phone as an emergency number.
To change the numbers defined as emergency numbers you need to act on these parameters
https://service.snom.com/display/wiki/emergency_numbers
https://service.snom.com/display/wiki/keyboard_lock_emergency
You need to REBOOT THE PHONE for these changes to take effect