Orignal Property Document linked to personal loan

Hello Sir I have taken a home loan of Rs 7 lakh from a bank in 2007 which is still in continuation. I have also taken a personal loan of Rs. 1.2 lakhs from same bank in 2006 without providing any collateral. Due job problem in the past I was not able to pay both the loans. After sometime I was asked to pay home loan due to the fact that bank may sieze the property since orignal documents related to property was in banks custody. So currently I am paying home loan and personal loan is still pending. Out of 1.2lks I have paid around 1 lakh and as per bank due amount was 52k amount was due when I stopped paying. But now since due to non payment bank has charged so much that the amount to be paid has increased to 1.67 lakhs. So bank is asking me to pay that much amount without which they are not going to release orignal documents . Below are queries regarding the same and need your guidance for the same 1) Can legally bank charged so much interest and other charges which is more than 3 times orignal amount. 2) Can legally bank keep documents in its custody though personal loan is not linked to my property. Please advice further course of action for the same