Apple ID locked for security reasons

I have an iPhone 5 that I want to completely start over with.

When I ask to delete and restore everything from my iPhone it tells me to put in my password.

When I have put it in it says that my Apple ID is locked for security reasons. When I ask it to unlock it I get directed to a site where I should change password.

When I change password and start again is just repeats itself and sends me to change my password once more, and so it goes, in som kind of loop.

What should I do? My phone is so slow and full of crap, I just want to start over...

Thank you,

Oskar