How can I reset the form - aka reverse the changes?

I did a mistake and used this module with a multi-page form. I know now that it's not supported...
It corrupted all pages and buttons show up at the top. When I refresh the page it gets fixed, but it comes back when I change the page.
I used the Reset Position Data button but it didn't help.
It would be a complete nightmare if I have to redo the form again! so please help.