Can't unlock my phone after changing to longer password

My company has requested that we move to a longer password on our phones. So I went into my settings and changed from using "simple" password (4 digits). It came up with a keypad and I entered a new 6 digit password instead. I decided to keep using numbers and not any letters. Now when I try to unlock my phone, the old numeric keypad shows up. I enter the 6 digits and nothing. The old 4 digits don't work either. If I keep trying, the company will wipe my phone. What can I do? I do have a recent backup, so maybe restore is my only option?

I am currently running iOS 7 on an iPhone 4s.

Thanks