I hit my Nexus 7 with Android 4.2 on it, into a glass bottle. Somehow, internally the battery got disconnected so it didn't turn on. It was only flickering a black screen when attached to a power cord. I didn't want to fix it myself so I brought it to a certified service for mobile devices. I received it back but it had installed Android 4.4 and all of the data was wiped out.
What did the people from the service do to my Nexus 7?