Problem with iPhone 4 after installing iOS 7?

Some time ago i downloaded the uTorrent iOS 7 for my iPhone 4 (I know it is illegal, and I know it would be a risk - maybe my phone would break down or something like that, so pointing out it was stupid I downloaded the uTorrent version is pointless now) and one night i woke up by the light on my phone.

I looked at it and the screen was all white with a black apple (it has always been black with a white apple) and after a while my lock screen showed up. I tried to unlock my phone but instead of unlocking it, a grey box turned up around the "slide to unlock" and then a voice read out loud what was in the box (so the voice said "slide to unlock"). Then i touched on the clock and again - a grey box around the numbers and a voice saying the time.So, basically everywhere i touched a grey box around the area i touched would appear and a voice reading what it says, it even said how much battery was still left and the name of my Wi-Fi.

I later figured out that if i clicked twice quickly at the "slide to unlocked" the phone got unlocked and it showed me that i should plug the phone to my iTunes. I did it, but nothing happened. My phone couldn't synchronize as it always could (even after I updated to iOS 7), and on my phone appeared a white background with a small black text saying: Your phone isn't activated, please download the newest version of iTunes and plug it in again.

The problem is now that I already have the newest iTunes, and still nothing happens. I can't do anything with my phone… I can't even restore it or downgrade it or anything else…

I really want to know if someone else has had the same problem with their iPhone? Or maybe some of you know what I should do? I was thinking of taking it to the store where i bought it, but since it isn't running the original iOS it should run, they will not/can't do anything about it… (And sorry if there's some misspellings, I'm from Denmark, so it isn't the best english, but I hope you understand my problem!)

Put your phone into DFU mode (this is how: http://www.iclarified.com/entry/index.php?enid=1034)

iTunes will detect the iPhone in DFU mode and you will have the option to restore it back to iOS 6.

I'm sure everything will be fine after that.

You need to register your device's UDID as soon as possible. Apple has been deactivating devices running unreleased software on unreleased devices. I registered my 4S on http://www.instantudid.com/ and I haven't had any issues.