Intent of 5 Percent Debris Extension?

There is a 5 percent extension for debris removal of covered property under the HO-3 forms. Stated coverage under the dwelling, other structures, and contents have been exhausted. A contractor charges an insured a lump sum for removing covered debris, which exceeds the total remaining 5 percent coverage available. He refuses to provide a break down because he says he cannot separate the cost to remove the contents from the cost to remove the dwelling debris. I am required to do so on the premise that each 5 percent limit is a separate limit, and the cost to remove contents should only be a few hundred dollars and not exceed the 5 percent limit, while the dwelling debris will greatly exceed the limit. What was the intent of the coverage? Is it an aggregate limit to be applied to debris removal since it is impossible to separate the covered debris? 

Pennsylvania Subscriber