Even if the burden of debt is like a mountain, (if this dua is recited) Allah will forgive the debt:

اَللَّهُمَّ اكْفِنِي بِحَلَالِكَ عَنْ حَرَامِكَ، وَأَغْنِنِي بِفَضْلِكَ عَمَّنْ سِوَاكَ

Allaahummak-finee bi 'halaalika ‛an 'haraamika, wa aghninee bi fadlika ‛amman siwaak

O Allah, make what is lawful enough for me, as opposed to what is unlawful, and spare me by Your grace of the need for others.

Reference: Hasan Gharib. Tirmidhi: 3563