OVERCHARGED INTEREST

Person A lend money to Person B an amount of money exceeding to 500,000 pesos.  Initial charging of 100K a month for 5 months and then followed with 10% per month .  However, person B was not able to pay anything.  The following year Person A continued to charged 10% a month.  Person B gave Person A a certain amount of 18K only due to non collection from Person B's business.  By end of that year, Person was forced to make a promissory note to pay 3% monthly to appease Person A.  The following 2 years despite of updates of the business, no payment has been made by Person B.  After three years passed, Person B was able to get something and paid more than 100K to Person A. The following year, Person B paid again another 100K and paid another 50K after a few months.  With good intention, Person B is updating Person A of the current business situation and expresses intention to pay as soon as collection is big.  The money according to Person B is being rolled and collection has been very slow.  Person B hopes to get big orders the following year and intends to pay

Charging 36% interest a year for a personal loan is indeed overcharging.  Is there any good advice how Person B who has a good intention to pay be freed from overcharging and be charged of what is proper in the law with maximum 15% interest annually.  This way person B can arrange for a monthly affordable payment.  Can this be possible and what actions should Person B do to make this happen? No legal interference has been made up to the present but Person B is considering getting legal help to ease this problem.