How to deal with a contractor not hauling away a "bagster"?

[Todd Runstein]

I hired a contractor to reroof a garage on our rental. He finished the job (mostly) and did great work. But, I made a mistake and took his word that he would have the "bagster" he used for the waste, hauled away. It's been weeks, and all I'm getting are excuses and promises that he'll get it taken care of.

There's a clause in the contract he had me sign saying that he would take care of clean up. But, since he's already been paid, I can't do what I should have done . . . withhold payment. Since that the train has already left the station, what should I do now? I want to get this eyesore removed before it pisses off my renters, but I don't want to pay for removal twice. 

Any advice is greatly appreciated!