Unauthorised Lien Marked On Joint Saving Account By Bank

Myself as well as my father have joint saving account in ICICI Bank.We together have not borrowerd a single penny from Bank till today,nor we have stood as surety for his loan for another account holder,nor we have breached any terms & conditions,nor there is any debt due,or any credit card due on the joint account,even though Bank have marked lien on our saving account. We first come to know abut this when we were unable to withdraw amount from ATM.Immediately we went branch office were branch manager said that lien is marked by head office,as there has been double payment made by your ICICI pru Insurance company on your account,which they are claiming for reversal.No notice or intimation was given by Bank for doing so.Bank manager said we have rights for doing so. Immediately i checked my policy documents,were i come to know that i hv surrenderd the policy in 2016 & surrender value has been already initaited by them in same year and account has got closed.Now after 3 years insurance company is stating that they have mistakenly credited double payment of Rs 27k on our account & with this effect they have provided written application to Bank as a result Bank has marked lien of Rs 27k.We as joint account holders in good faith have used the amount it was transferred legally as surrender valule provided by Insurance Co also there was not any objection within 3 years. Please put light on Bank action fall under principle of lien & is it justificable.Please elobarate. What is the remedy to remove lien as i am convinced that both Insurance Co & Bank are separate legal entities.Contract with Insurance company is already extinguised in 2016.