You would need to add credit to your account to do so, and the costs are very high. For example, data is 10p per MB (about £100 per GB) in Brazil, 25p per MB (about £250 per GB) in Argentina. It would be much cheaper for you to get a local SIM in Sou...
This is a discussion forum where Smarty customers can help out other Smarty customers with advice.You'll need to chat to Smarty support to arrange for a replacement SIM to be sent out (to your home address.. they won't be sending it to Egypt).
Some phones will use mobile data if they detect that no internet connection is available through your WiFi connection, or if the internet through the WiFi connection isn't working well (I can't speak for Android but I know iPhones do this by default,...