Why won't my tension pulleys rotate?

My serpentine belt was in shreds when I raised my hood after hearing clanking noises. I took off the old belt and put on a new belt. I tried turning the tensioner to the right to tighten the belt but it won't turn to the right. In addition, the entire tensioner itself is loose. Also, I turned on the engine and the tension pulleys won't rotate. Could the tensioner be busted? Or the tension arm assembly? Please help. Thanks in advance.