mobile data off

What to do when mobile data does not work on the Andrdoid device?
not only iphone but also android users also have the case of using mobile data (3g, ...) but cannot access the network. in many cases it is necessary to not connect to 3g network, making users extremely uncomfortable.
The American family panicked with bills of more than 300 million Internet money when returning home after a trip to Vietnam
chung's family, who lives in san joe (usa), came to vietnam to travel and when they returned, they were horrified when they received the data bill from t-mobile with a total of over 13,000usd (more 303 million vnd.