Huddarudder

hi all, apologies this is all brand new to me and i don't really know if this is even going to been by anyone, but i'll try. My 2006 525i rear left window is stuck in the 'down' position. it does not go up or down. All the posts about the rear window anti-trap feature refer to getting the auto button working again, and i fully understand that -but my rear window is stuck in the DOWN position, clearly not convenient. When i push or pull the window button - i can hear the motor turning, but the window is not attached. And then it comes us with "anti-trap rear window failure' warning notice.... how do you suggest i can get the winder to attach itself to the window again? I'd love some suggestions to avoid paying $500 at the local stealer... thanks and cheers