Restored iphone keeps asking for icloud account that's not the one I used

I have an iphone 4 which was given to me by a cousin, when he handed it over to me I personally replaced his previous information with mine, including that of icloud. I had been using this phone for about 4 months already. Due to an update needed (as told by my carrier T-mobile) I was advised to restore the phone.

Yesterday I did this restore, and before doing so I turned off icloud's "find my phone" off.

Now that the phone is restore it is asking me for an icloud account that belonged to my cousin who gave me the phone, we know the email but not the password.

What I don't understand if, if I had already set the phone up with my email when I received the phone, why is the previous owner info the one showing up, I had already replaced that…

Now I'm stuck, my cousin has tried everything to remember or recover the password to his old email (which is the one he used on the phone when he had it) but no luck.

Is there anything I can try?

If you get a login error when connecting to iCloud, login on this webpage:
http://me.com/move

If it still does not work, it means that Apple servers failed to check your password.
You can change your password on this page to workaround this issue:
Connect to
https://appleid.apple.com/....apple.com.
Choose "Reset your password"
Follow the instructions.
Then, your iCloud account should work fine.