Credit First, N.A. review: Unjustified late fees

Their statement arrived late. I paid the bill in full, but then they kept sending me notices for late fees. I refused to pay them, because their statement arrived late. Their harassers did not care, they kept calling and they've charged increadible interest on the late fees, going from $35 initially to over $230 three months later. I repeatedly asked to talk with a manager and they refused. They are inhuman, crass and ruthless.
PS: Firestone, too, is corrupt; they tried to get me to replace front brakes for nearly $500, and when I got another opinion, I was told the brakes only needed to be cleaned for $80 ... and that was correct, because 3 months later, after the cleaning, the brakes are still fine.