iCloud is defaulting to an incorrect id on my iphone 4S
Whenever I access my iphone for anything I continually get asked to enter the password for my iCloud account, not a problem except that the iCloud id it comes up with is incorrect by one letter. I cannot see where to change the id. No password I would normally use works. Online I can sign into the Apple ID it should be but not the one it thinks it is. I cannot reset the password for the incorrect id as it is an email address I do not have so I cannot access the emails that are sent to reset. On the iphone I have the option to sign out under settings> icloud but I have tried this and cannot complete it as it just asks me to enter my password to turn off find my iphone, which I don't know as its asking for the password of the incorrect id. Help - how can I change my phone's settings so I can log into the correct apple id?
iPhone 4S, iOS 8.2