Add-on Pack for Global data package
Jim purchases a Global data package to use. There is not much data left in the package when he reaches Thailand but it is still valid for a long period of time.
He chooses to purchase a 300MB Thailand Add-on pack and activates it after the purchase;
However, Jim receives an urgent notice that he has to go to Hong Kong immediately. He takes off to Hong Kong and purchases a Hong Kong Add-on pack. When he reaches Hong Kong, he activates it and uses it;
At the sametime, his Thailand Add-on pack is still valid, when he goes back to Thailand, it still can be used;
Jim leaves Thailand and goes to Italy. This uses the remaining data in the global package.