I have an iphone 5 on Verizon with firmware 6.0.2. I jailbroke my phone with evasi0n a while back with a version that only supported the firmware 6.xx but on the iphone 4. At first the only problem I had was that airplay and bluetooth didn't work, which didn't bother me too much. Subsequently my phone couldn't connect to wifi (I think this is more of a 6.0.2 problem rather than a jailbreaking one). But now a third of my phones memory is taken up by 'other' on iTunes, (I don't that many jailbroken apps). I've read that this could be caused by an error in the code of cydia that keeps multiplying and taking up memory.

To fix this I tried putting the phone in DFU mode but I get a popup from itunes after saying that it is verifying with iTunes. The popup says "This iphone could not be restored. This device isn't eligible for the requested build". The same popup has come up when I've tried to restore it out of DFU mode.

Does anyone have any ideas as to what to do with it?

Thanks