I have a Samsung Galaxy SL I9003 mobile phone. I prefer to use 2G data connection instead of 3G but I am unable to turn off the 3G service in my phone. How can I turn off the 3G service and use 2G instead?
Head over to the settings> Under Wireless and Networks>Tap More Settings>Mobile Networks>Network Mode>Change it to GSM only. This will keep you over the 2G network, when ever there's a need of 3G network again in future then you can again change it to auto mode.