Share your experience!
First of all, I have to apologize for any language mistakes that I will (might) make, since English is not my native language - so, SORRY. 
Second... I bought MyPrecious in July this year after my LG unexpectedly died (I wasn't really too sad about it, because I was already looking to buy a new phone), so I had only 3 days to figure out what to buy (price range was the biggest issue, as it often is). My boyfriend has some big a** Sony phone and he's very happy with it (I think he said this is his 3rd Sony in a row and now he's waiting for that new Z3 thing to come out), so I bought Xperia E.
All was good. For a while.
At first MyPrecious stopped recognizing headphones. It would recognize them every 10th time I would plugged them in, but even that was working for maybe 3 days. At the end, it just stopped.
So, since I still have warrenty, I took it to the shop and they sent it to service (ah, that imaginry building with all those people that pretend they know what they're doing.. That's, at least, what it looks like in Croatia). 10 days later, MyPrecious came back and apparently motherboard had to be exchanged. It look naked and not like my phone at all, but at least my headphones worked. So, I started to make it look like MyPrecious again.... That day I connected it to Internet via my home wi-fi, downloaded my apps that I "can't" live without, set up my background wallpaper and all was the way it was (except for my data - I lost that...........). Then I checked if my data traffic works, all was OK and I went to sleep.
Morning came, MyPrecious happily by my side, wallpaper still on, but not way of connecting to Internet.............. Wi-fi - nothing. Data traffic - not even in my dreams. My computer works normally, my wi-fi is stable and works perfectly, but MyPrecious refuses to connect in any way.
Two days later, I finally connected MyPrecious to that PC companion thing (not sure about the correct name of the app) and went through updating and "don't touch your phone, don't touch any cables or breathe while this is running" and restarted it few million times and NOTHING.
I gave up and went to sleep. MyPrecious still on (I don't turn off my phone during the night, so...).
Morning came, I tried to connect it via data traffic just for fun (something to do while I had my morning coffee) and nothing, but it connected via wi-fi like it had no issues at all in the meantime..................... I flipped!
To summ it all up - it connects via wi-fi, it's up to date, it doesn't connect via data traffic (and I checked on another phone - my data traffic plan still works and all is OK with my SIM card or whatever you may think to ask about that), it did connect via data traffic the first day I got it from the service... I didn't click anything in the meantime to disable data transfer - I just went to sleep......
There. That's my story. Any suggestions? Ideas? What should I do (and I'm not in a mood to take it back to the shop before I try anything I can to "fix" it myself)?
Sorry to take up lots of your time with this long..ish story and again, sorry about my English skill (still learning!
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Thank you in advance for any advice/suggestion/idea you give me, because I really, really like my Sony phone and I would hate to switch back to LG again (or God forbid - iPhone :D).. (Just kidding, LG's OK, but I'm a Sony girl)
Have you downloaded and install the correct settings for your metworks Data and MMS - Settings then More then Internet settings then wait and select your correct network - Some have two ie: PAYG and contract so select the correct setting then it should work - you could also try performing a system repair as this will often fix issues - This will factory reset your phone
Switch off your phone and unplug from Pc (Hold volume up and power for around 10 seconds)
Start PC Companion and select Support zone then Update my phone/tablet then in Blue Repair my phone/tablet and follow the onscreen instructions - When prompted connect your phone still switched off holding volume down or back button - This should start the repair or reformat process
If you are using Windows 8/8.1 or a 64bit operating system then adjust the settings for PC Companion and run in compatibility mode and chose Windows 7 or XP
Been there, done that, nothing.............................. 
Did all you suggested, didn't help. Wi-fi works, data doesn't.
Aarrgghh...
Any other ideas? 
Get a brand new SIM card
FIXED!
I went to the shop where I bought it and the guy spent over 10 minutes trying to figure out what went wrong.
My mobile network APNs were all deleted. How? I really don't know. All was working one night and all was deleted in the morning. But, whatever happened, he fixed it and now I know what to look for in case something like this ever happens again.
But fun thing happened yesterday - MyPrecious restarted by him lonesome self. It was on the table and no one was touchung it. I suspect I have a broken/faulty machine there...... Not good for convincing me to stick with the brand.
And my SIM card is new - maybe 3 months old.
Anyway, thank you all for your help!
from Croatia 
Anytime