Crushed heating ducting – 8″

Hi there, I did some work under the house on the weekend and crushed two sections of 8″ flexible ducted heating pipe, likely both need to be replaced as I couldn’t un-crush them. The crushed sections are near the central splitter from the 12″ pipe, and about 18″ crushed, so maybe 2-3′ of both pipes need fixing. The section under the floor where they are is only high enough for wiggling, not crawling. Can you let me know if you can help out (and approx how much)? Thanks, Alex