You need to write a letter to the bank branch

Offering remote work. It is necessary to write a letter to the head branch of the bank "AbsoluteBank", with a request for the total amount of proceeds from the sale of an apartment accepted on the bank's balance sheet after 2 failed biddings. The amount I know, the bottom line is that the difference between the price at which the apartment was accepted by the bank (-35%) and the price of its further sale (market). There is a 500 000r difference, the bank should have written off my debt, but it does not do that. We need to close the mortgage agreement.