Soumya and Mangal, both took a loan of Rs.4000 from a bank, at the same time. Both needed to repay the loan after a time period of 2 years, compounded at a rate of 15% quarterly for Soumya, while compounded annually at a rate of 20% for Mangal. Find the difference (in Rs.) in the amount needed to be repaid by Soumya and Mangal, at the end of two years.