How to turn off mobile-data/3G for each SIM card separately in Samsung Galaxy Mega Duos? I'm using Samsung Galaxy Mega Duos and use two SIM cards - one sim with very low charge for 3G connection (called SIM1) and the other with very-high fee (called SIM2).

I go to Setting - Connections - Data usage to turn off 3G on SIM2 but the checkbox Mobile data seems to be synced between the two e.g. if I check it on SIM1 and then go to SIM1 to turn it off, SIM2 is turned off too!?

My question: How can I turn of 3G for SIM2 but keep it for SIM1?
I had the same issue. Found this solution on another site:


Open "Settings" App
Go to "SIM Card Manager"
Tap on "Data Service Network"
Choose the SIM as the Data SIM


Note that only the first SIM slot supports 3G Internet. So if you want to use 3G you must plug your 3G SIM in the first slot.