Need you help to respond Cashe to collect my actual agreement copy

Respected Team, Just need one help assistance on below matter, which is seviourly going to other directions in my life > I had applied a loan from Cashe, where i did not confirm any agreement to them > Without confirming any agreement, they credit an sum of Rs.50K in my account & same date i informed them. > Rs. 50K has already been refunded to them on very next date. > Now for me challenge is appearing that they are demanding that another 50K need to pay. > When i asked for the agreement, they are not ready to share that agreement > I asked them how much amount they had creditted as per their record, so that i will check with my bank account & pay that amount, Even that details also i am not getting from them > Each day they are sending reminder email & depositing request for ECS , which was rejecting by bank > Recently i also faced a scam in my wife account, due to which i am requesting for them authorization, but they are giving me threaten notice In the above case what i should