I cannot get two way verification as my mobile number is not recognized by Apple

I cannot get two way verification as my mobile number is not recognized by Apple. My mobile number is in a place called Gibraltar, which is positioned south of Spain on the Iberian Peninsula. Its not the Gibraltar on the East coast of the US!
We have our own government, police force, etc plus and incumbent telecoms provider called Gibtelecom. The country code is +350 but Apple do not have this code listed. The more annoying issue is if I want to ask Apple support to help me, I cannot as APPLE do not list the country code so they cannot call me in 2 minutes/later/schedule a call!
Any idea's would be most welcome.