Unhappy [Q] [HELP] [C6903] 3 Feet Fall!!!

Hello guys.. I have a big problem here.. I fell my C6903 last Saturday from 3 feet! D'oh! But surprisingly it survived! It's even not powered off when dropped! No dead pixel, camera is OK, everything is fine. But my ASF is totally broken. It's only cracks along screen, after I pull it out, here it is.



Today, I wonder if my phone still survive underwater test, so I test it. It's just 5 minutes. Everything is fine. Untill...

1. First 5 minutes -> Something wrong with my light sensor, screen is dimming and brightening randomly. D'oh!
2. 2 minutes after first 5 minutes -> Volume up and down randomly. D'ooh!!!
3. 2 minutes later -> Hard camera button going crazy!
4. 2 minutes later -> Screen totally dead! Nooo!!!

I bought this C6903 at December 2013. These are my C6903 condition

1. Under warranty
2. No ASF (no Sony logo anymore)
3. Bootloader has been unlock (Without TA Partition Backup!!!)
4. It's still alive, I can charge and my Laptop still recognize it.
5. It's INDONESIA - JAKARTA

My question is

1. How to claim my warranty? I know about "playing fool", but can you give me suggestion to talk to them without look suspicious. I'm sucks at talking
2. How if I hardbrick my phone? So they can't trace my bootloader status.
3. If hardbricking is a solution to avoid me looking suspicious, HOW TO HARDBRICK my C6903?

Need help ASAP. I need my C6903 this weekend.

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Update

1. Volume up is always pressed, so press and hold power button actually will hard poweroff the device
2. Since volume up is always pressed, I can only go to flash mode
3. Connecting my devices to wall charger won't make it go to normal boot (it stuck on something, IDK)
"It is not the size of the sword... It is how you use it!!!"