Bank has lost 2 documents out for 4 Original documents

Hi, Bank has taken 4 Original documents while sanctioning loan to me · Sale Deed · Agreement · Agreement to sale · Encumbrance Certificate. Same is acknowledge by bank by providing list of documents twice held by bank. Now after paying full loan amount they are saying they don't have Original documents for 'Agreement' and ' Agreement to sale' and when I requested them replied like this "As explained, you have been demanding to return the two original documents alleged to have been deposited with the Bank i.e., Unregistered Agreement and Unregistered Agreement to sale. This is owing to the reason that the Bank had, due to inadvertent clerical error, acknowledged receipt of documents. We humbly submit that the acknowledgement provided by the Bank on October 25, 2010 and July 28, 2011 were erroneous. To corroborate the said fact, we submit that the list of documents mentioned in the said letters bear a mention about two documents, which are in no manner connected to your property. For the sake of clarity, the copies of the said unregistered documents bear no mention in the list of documents provided by the Bank on the dates mentioned in our above stated acknowledgement letters. Hence, due to the said reason, the alleged originals of the said unregistered documents were never received by the Bank. Hence, the return of such non-existent documents is not feasible, and is beyond the control of Bank. We have engaged with you extensively and have clarified the aforementioned position. We have also tendered an apology for the typo/clerical error. Further, as a matter of abundant caution, the Bank has also sought legal opinion on loss of the aforementioned two documents. Through the opinion received from our legal counsel, we have ascertained that the unregistered documents would have no bearing on the title of the property and does not in any way affect the title or valuation of the property. We believe that the Bank has been extremely transparent in explaining its position to you. Given that the inadvertent typo/clerical error has no material impact to you or to the title or valuation of the property, " What should I do? can I file a case against bank to not returning all original documents? I have proof when they asked for all originals and acknowledgement for list of original documents. But now they are saying it is unregistered and it will not impact on title or valuation of the property. But if they have taken the originals then they should return also else compensate if they have lost it. Can I ask for compensation? if they don't agree then can I file a case for not returning original documents?