TVSNTorq model no Two wheeler - Harrasment and forcing of payment

My brother has bought the bike in **** jan but he died in May **** and we have done the claimaint process to the muthoot office staff but he didn't submit the docs to the office. Again we have submitted in the year **** but still it's got somehow not submitted. In between many collectors came to collect the emi but we repeatedly said they the person us no more and we are not able to pay the emi as I have lost father after * months of brothers death. Again in the year **** jan we have submitted docs to the muthoot office and they told that it has settled with insurance and rest ***** we need to pay we again convinced them that it is not possible for us to pay any money.
After about one year on **th jan received one letter and also attaching the letter.. There it has written we need to pay the money along with the interest.

Kindly suggest and solve as we are not in such a position to pay the amount.

In whole process everybody has just taken the everything casual and we are also don't have idea about this loans emis.

Kindly help.