iPhone Please help my iPhone is gone for a week now

im new in here, new to apple world too, my iphone 4 is factory unlocked, turned off suddenly last week then when i plugged it to the connector showed connect to itunes, i did a restore n updated to ios 6, first kept showing error 21 then after a few times it restored fine, and i chose to set it up as a new phone, but got stuck in a reboot loop, it shows the apple logo, then the slider n says slide to configue, whether i slide it or no it disconnects and restarts again!!!

i tried all tricks online DFU mode, or restore mode, 2 cables, 3 different computers.. still the same...
any other way to fix it?
can i do custom firmware on a non-jailbroken phone? i downloaded ios 6.0.1 but scared that if i restore from a file other than i tunes my phone will brick

it's the last choice cz i called them they said the only way is to replace it with another and they'll charge me $190

dhlizard said:

If it's not a battery issue (charge it on the wall charger overnight) it will need repair.

We cannot make that change. Sounds like you have 3 options:

1. Let Apple replace it
2. Take it to an independent repair shop (can be risky)
3. Buy a replacement phone.

Click to expand...

u r right an independent technician is risky, they might open it and i lose the chance to replace it in the apple store.. besides, he wants half the cost of a new replacement from apple!!