485 pending at Nebraska Center

My I-485 pending at Nebraska center since Jan. 2002. The current process day is May 31, 2002. It has more than 4 month overdue. I call serice center to inquire teh status. I got a letter said that "due to case overload at Nebraska center, my application need longer process time". Thie reply is a lie. Since my case is long overdue, that case overload should be already included. Any body has such bad experience at Nebraska center?