Maternity Leave Salary For Guest Teacher In Delhi

I am working as a guest teacher in Delhi since 2018. Guest teacher contract was ended on 8 May 2020 renewed on 14 July 2020 and also due to summer vacation in June my working days in the month of June were zero. I had given birth to the baby on 24 SEP 2020 and had applied for maternity leave from 16 SEP 2020 to 14 Mar 2021. Now for the calculation of salary during the leave period average salary of three months previous to the month of leave applied is taken into account but in my case, the school is considering the month of Jun +July + Aug which gives me an average salary of 12 {(0+15+21)/3= 12} days per month since number of working days in Month of Jun and upto 13Jul was zero. This calculation gives me Half of the salary I m suppose to get. Please guide me about the matter.