I can not restore an iPod Touch locked with a passcode

Let me first start out by saying that we work on iPods every day so I am surprised that I can not resolve this issue...

I have an iPod Touch 4th Gen unit. It came to us locked with a passcode. I can not restore it with iTunes as it says it is locked with a passcode. I have tried every which way to put it into DFU mode but I keep getting the iTunes pop-up stating that it is locked.

I need some help to know how to simply restore this as it is like it has a kryptonite password. I can not even get it recognized by my Windows system when I plug it in.

Again, I have tried all of the power/home button remedies to put it into DFU mode and none of them work.

Do I have any options?

Thanks,

Rick