Renault Grand Tour 2.0 Privilege - Year 2011

Hello good morning
I need a suggestion. I have a Renault Megane 2 Grand Tour 2.0 - Privilege year 2011. From one moment to another the ignition was blocked. Send the car to the Renault dealership and after resetting the computer, they told me that I had to change the steering column lock, address column and starter reader.
In factory they do not have those spare parts and they will not receive them, look for it in renault houses and tampo have availability. Can anyone suggest who can rectify these components in Argentina?
I appreciate the suggestion they can give me.
Thank you so much