ita!i'm so sorry that happened to you, and i would take it to chanel, and see what they can do!
I have a vintage black lambskin mini flap and it was fine when I wore my denim skirt which is very stiff and rough.I have Chanel lambskin from decades ago and it doesn't rub off! Is that a stain or did the leather actually rub away? Does it feel rough to the touch?