International Super Roof, Ltd review: Roof warranty not valid - unable to locate or contact

Roof has 50 year warranty when installed April 28, 1994. There are several leaks. I am unable to locate anybody to address this problem. All phones have been disconnected or changed Internet searches do not bring up anything but this website I am responding to right now. Do you know of a way to find a company that was so large, the paperwork shows branches in other countries, along with seven states here in the United States.