I have a annoying glitch(Xbox 360) with a companion quest to rescue Anrem from Serpent's Bluff Redoubt. I get there, fight through get to his cell which is empty, kill the people guarding it. I then get the completed rescue message and am asked to talk with Anrem and guide him back to Whiterun. However he isn't there, on the map in indicates him to be at the door of White run, though the quest point still highlights Serpent's Bluff Redoubt.

Back at Whiterun, it indicates his position on the door itself. Go in Whiterun it points to go back out, go out and it points to go back in?

So I thought, he must have died earlier somehow. I then went way back in my saves completed the enter the Companions quest, on my way back there to get my first task from Vikas, I bump into to Anrem alive and well !. Then speak to Vikas who says he's been kidnapped, go back to rescue and bam, he goes missing again, same thing happening.

Please, please help with an Xbox 360 fix or work around because i can't move on as everyone says I need to complete the given task.