Make sure APN settings are correct. Also make sure the SIM card is in properly in the correct direction.
You like this post
Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth
Go to system settings>wireless & networks>more>mobile networks>Access Point Names
It should be automatically set to your network provider, if not you can manually add it. If needs be a quick search will find all the settings you need.. Same with the 3G Service option - check to ensure it is enabled.
Agreed - would bug me too, but at the same time at least this is a cheaper / quicker solution than sending back to china & hoping for a repair/replacement/refund.
Now if only battery drain could be sorted so simply! Lol