It's best to trust God and help those in need by lending money with 0 interest, when God says that he will return much more than you lend others back to you one way or the other, you just have to trust him enough, you know.
At some point God will have to understand that the interest charged is a function of risk. The interest charged by sashan serves to compensate people who, as in this case, defaults on a loan. I remember two cases of people who were lending and in the end they stopped because of defaults they ended up in losses. If they do not charge interest the losses would be greater, and God is not going to come to this life to compensate them for the money lost, in any case we will see what he does in the next life.