Dear madam,
You should have clarified whether your maternity leave is under ESI Act or M.B.Act.
Your sanction of ML by MD and subsequent telephonic communication about your termination while on ML is verbal.
The act of denial of ML and termination during the ML by the company is in blatant violation of the legal provisions and is grossly unjust. The company officials have committed grave and illegal acts against you.
But everything is done verbally. So my advice is as follows:
1. Don't get panic and do not, I repeat, do not resign in huff.
2. Engage a good labour lawyer and send suitably drafted letter putting all sequence of events factually , chronologically and demanding full maternity benefit.
3. Since the company cannot legally terminate your services, ignore all verbal communication and join duty after your ML.
If they do not allow you to rejoin, threaten them of legal action and follow up the same in consultation with your lawyer.
If you have to leave the job, it has to be honorable exit after receiving all legal dues including full ML with benefits.
Regards,
Vinayak Nagarkar
HR-Consultant