CRAZY battery drain

[OMG OMG OMG]

Hello, guys. I got my HTC 8X (Europe/International Edition) on 1st of January (2014). I used it for 15 days without any problems (battery worked for a day, even TWO days). Then, I installed all updates (GDR1, GDR2, GDR3, and some small updates). And this where it all began. I started experiencing CRAZY battery drain. My phone discharges in 6 HOURS (without any apps installed, Battery Saver enabled, even Airplane mode don't help). I don't know what to do... I tried doing hard reset (36 times!), going through charge cycle, turning on Battery Saver & Airplane Mode (as I mentioned before). I tried calling HTC support (via Skype), they say "it's hardware problem, go to HTC Service Center" (actually, there's no official repair centers in my town). But, I'm sure it's software problem! Everything was great before I updated...

After googling some time, I found this. Actually, no word about battery drain, but maybe, GDR2 is the problem?

Help me, guys. I don't know what to do.
:unhappysweat:

 

[mikey2toes]

Gdr2 was the problem but was fixed in gdr3. What OS version do you have? Settings> about> more info. Use the phone as normal for a week, bring it to below 20% and let it fully charge to 100% at least twice in that time, and it should start to discharge as it should. It will discharge quick with heavy use. I have the 8x and it was like that at the start.