Do not buy Samsung

Samsung wants to be a leader? It begins to produce quality phones, supporting 4G.
After buying this phone, with some pride ... I keep having problems connecting to the mobile network: the internet works but not the voice (incoming or outgoing), and totally random , especially when I get home or I go out of a building. Following communication with the Samsung service center, I did a reboot, nothing has changed, except that I lost some of my data despite using the Kies software to backup and restore.
Tip: Do not trust Samsung, or his service.