Iphone will not restore or update?

I have an iphone 4 and when i try to restore/update it an error code comes up saying "this device is not eligible for the requested build" i have done research and supposedly that happens when you have jailbroken iphone. But the thing is my iphone is not jailbroken, although i did start downloading the software once but chickened out. So i never did have cydia on my phone and i thought it was normal, but apparently there must be jailbroken files on my phone i just can't see them. My phone looks and acts like a normal non-jailbroken iphone yet that error code still comes up. This is frustrating because i just got a new phone and can't restore my info onto it. How can i fix this?

Sorry you had to buy an Iphone, there's little hope take it into an apple store with a receipt, otherwise they will not help you

Back up all your info first then put your phone into DFU mode then connect to itunes and restore. It will probably ask you if you want to update. Then after you update set it up as a new device incase there are jailbreak files on it so they can go, then restore your phone from your back up