Please help.my android cell is locked

I have a Norton Mobile Security installed in my Galaxy Gio phone.I got it from Samsung Apps. When I took the SIM card from my phone and turned it on again, it locked. I tried every password and PINs i know, but nothing worked. I also tried unlocking my phone by making one of my buddies text unlock on my phone, but it did not work, too.Please tell me what to do.It has been locked for two weeks by now, I think.