@pazmariano reset your network settings and restart the phone. Samsung's will usually propagate the correct APN settings for the phone.
Enable data, Restart your phone, reenter your wifi if applicable. Try sending an mms text message and to surf the net. Stay safe. Welcome to PM.
@pazmariano restart your phone, enavle data and try to send an mms text message. If that works, your APN settings are correct. Log into your self service account and see if you have data available it should look like xxx/ 250mb at 3g speed. See below.