Lost of original property papers by bank

I have purchased a property in 2010 for which we took loan from the bank. Now in 2017 I want to transfer my home loan to some other bank who is offering me home loan at a lesser rate. When we asked our bank for our original papers we came to know that bank has lost our original property papers. It was us who has notified after 7 years about our original property papers. Bank has never informed that original papers are not missing with them. Now after our regarous follow ups, bank has agreed to borne the amount which will be required to pay during the procedure of certified copy. As per latest update bank is saying that they have arranged for the certified copy and want us to sign an idemnity bond stating in good faith bank acknowledge the lost of original documents and in good faith will lodge an FIR and advertisement in news paper. Also stating that in future customer should put any case against bank in any court and neither in consumer forum. They are asking us to sign the bond and after that they will lodge FIR and advertisement. Please advice what has to be done. Should i put a case against them? Will i get any compensation for that? Will the price of my property come down with this certified copy if in future i want to sell? Kindly advice on this.