How to delete itunes account from apple without the password?

I bought an iphone 4s from kijiji. The top button does not work but it's still signed into an apple itunes account and I don't have the password to delete the phone from that account. Is there a way of doing this

If it has IOS 7 you just bought an expensive paperweight. Without the password to the Apple ID is is impossible to restore the phone. You will have to get proof of ownership and talk to Apple. But even then there's nothing tech support can do for you either.

I'm trying to delete my itunes acc, but after 1 minute it tell me another one from i don't know who, i can get acess into my stuff now, i need a help