Can not unlock my LG VX4500 cellphone

Question

There was a lock code on my phone when i got it so i changed it to one of my own but the problem is i have forgotten what i changed it to and so i call the tech support operator,she says take to the nearest Verison Wireless store and let them reset the phone for me but the tech. there says the phone will not let him get into the system when he connects it to his computer. Is there nothing i can do? Is there not a master unlock code or something,or am i just stuck w/ a useless phone now?