Navigation on Samsung Galaxy s3 not working

Hey all, 

I bought a Samsung Galaxy s3 from AT&T outright, so I could use in Argentina. However, I am using a local service provider called Personal in Buenos Aires. My Navigation app was working fine and all of a sudden has stopped working and asks me to accept the AT&T terms and conditions, once I accept it requires me to enter a AT&T wireless number, Which I dont have as I am using the phone with another Provider in Argentina. 

I would like to know is it possible to change something so that the application doesnt request anything from AT&T and uses Personals Wireless instead. As I really prefer using the current original navigation rather then downloading others.

Thanks for any information in advance.

George