If the counter party willing to hire loan shark to collect the defaults it really means your uncle really kaki busuk fella, he shouldn't avoid not paying at the first place and when this happened he really asked for it.

In business when there is debt default it's pretty normal , instead of negotiating how to make payment with the counter party or work a way to pay off like sell assets ,but then again it's too late at this stage, mind you the fee hiring loan shark bear by your uncle , the debt will be more than the initial amount owed

The best solution is quickly pay off the debts by all means, start selling assets or take loan from banks if can't pay worse to worse bankrupt akpk which is better than ah long