I thought all of the world pronounce it their way.
Ie. in Poland it is 'ik-eh-a' (although in fact, only english acronyms are spelled english way ie. 'beh-em-vuh' instead of 'beh-em-veh', but KFC as 'kay-ef-see')
Actually faen is the right expression. When talking about the devil we could use satan, but very seldom would faen be used as a other word for the devil.