Out of territory loan borrowed and harassment by recovery agency

My wife had a loan and due to some unforeseen circumstances we were not able to return to UAE and couldn't pay up the loan the last installment was paid in September 2015, now there is this agency who is following up with us they call and talk nicely but their field Agents are trying to threaten us, we have informed them since we are jobless as of now we need time, also they have not provided us with the banks authorisation letter and the settlement amount is also informed on a piece of paper hand written there is nothing on a letter head given to us, when we asked for the documents they gave us couple of pages of the application form and copy of the passport on the file those were the documents the agent carried with him and I took a copy. So there is nothing black and white given, no notice not even a bank letter and every alternate day call and field visit, plz note the threats come via field agents only, I keep on telling them plz give me time but they are persistent, with their follow up. I am not sure what to next. This has been happening from a little over two months now, my parents are old and this is the reason why I have not approached a police station yet also since the threats come via field agents only there is no proof plz advice