Who are the Thernadier?

"The belong to that bastard class formed of a low people who have risen, and intelligent people who have fallen, which lies between the class called middle and lower, and which unite some of the faults of the matter with nearly all the vices of the former without possessing the generous impulses of the workmen, or the respectability of the bourgeois." (Hugo 45) Madame and Mosuire Thernadier are a pair of decievers who dont feel pitty. They heard Fantine's story and it doesnt matter how miserable it was, they still found another reason to charge her extra money.