device access code on router is incorrect

I'm trying to change the firewall settings on my BGW320-505 router and it says the access code is incorrect. I tried clicking forgot code and when I typed in the default code on the back of the router it once again said it wasn't correct. I am 100% sure I'm typing it in correctly with no mistakes in capitalization. I don't know what to do other than call AT&T to get a replacement which I really don't want to do, what other options do I have?