I've just bought a Samsung S7 sim free and it is unlocked to accept all EU sims. I've been advised that the phone will not accept a non-EU sim card. I need to use it in a non-EU country. Is this true and if so, is it possible I can unlock so that any sim worldwide can be accepted? What's the best way to do this? It is likely that the guarantee that comes with the phone will be void if i unlock? I am surprised the Samsung store doesn't unlock to accept word wide sims!?