Public Ltd co. not extending leave after availing ML

[sangita_sawant]

I am working with Public Ltd.co.from last 3yrs & was on payroll from Apr12. I was on maternity leave from 26th nov 13 to 23rd feb 14 (90days) as per co's rule I have to resume duty on 24th feb. Therefore I resumed office for 1day & apply for further 3mnths leave extension. But now they are not ready to give me extension for another 3mnths & sanctioned leave only upto 18th march 14. My new born baby is just 2&half mnths till 18th march & my baby sitter will take care only after baby will complete 4mnths. I request my seniors but they are not ready at all, so now what can I do if I want to take another 2mnths leave. I am having 50PL balance and also ready for LWP. Shall I apply leave for medically unfit as I had an C-Section, if yes then when can I apply either on or before 18th march 14 as they extended leave only upto 18th march.
I need help what can I do as I don't want to resign and worry about what will they take action if I have not join from 19th March 14.