Debt recovery

Hello, I own a small engg workshop and I'm not paid by a public limited company for successfully completed work orders. The dues are more than Rs. 25 Lakhs (have purchase orders, customer took delivery, have delivery challan and material acceptance notes from that public limited company). There is also another set of completed work orders for another Rs. 30 Lakhs that this company is refusing to take delivery inspite of sending reminder notes and proforma invoices to them. I have sent remainder emails to the managing director, CFO, VP's and purchase order teams but none of them respond to my emails and when i go their office I am not allowed to meet the MD. All the work orders are more than 6 months old. So, how do i recover my dues from this public limited company? How do i ensure that they pay and take delivery for work orders they refuse to take delivery? I went to a law firm and they say i need to file "winding up" case. I read about winding up on google but not convinced. so please help in cases that i can file against the management of the public limited company refusing to pay me.. Can i file IPC 420 case against them? What recovery suit can i file in the civil court and under what CPC sections? How time does it take to case closure? Can i ask the civil court to pay for principal and intrest charges? What is your suggestion on winding up suit? Can i file all these cases simultaneously? What is arbitration? I read this one possible option Kindly help with your suggestions. Thanks.