does anyone know what happens if at the end of my iva not all of my creditors have put in a claim, do i get any money back?

Since starting my iva i have had letters from my creditors saying they have sold my debts to another company,ive had my iva for 2 years and was wondering if i could make my new credititors a offer to end the iva early and how do i do it?

Can i claim my unfair bank charges back from the same creditors i have entered into an iva with, most of them have sold on the debt and will it affect my iva?