my I phone is disabled and I've been locked out.

I have tried every thing online to restore it but nothing has worked. tried connecting it to iTunes but it asks for the password that i forgot. I have tried restoring it from iCloud but the phone is not connected to the internet because its disabled i guess, and i have tried shutting the phone off hold the home button and then plug in the usb cord but it says (the iPhone "iPhone" could not be restored. This device isn't eligible for the requested build.) when i hit update and restore. frustrated and need help please.