Tech Mahindra — Pending payment for more than 1 year

Address: Tech Mahindra, Hyderabad

My name is najeeb, and i am the founder of a 1.4 years startup scivoc healthcare consulting. My company provided medical writing services to tech mahindra, hyderabad last year may 2019 and since then they have not issued payment due to internal process irregularities. I am currently dealing with the office of ombudsman for a year to get the same payment. I had questioned their internal process and guidelines of working with the intent to fix it but since then my payment has been pending as the people from tech m have resigned and the current team says they are fixing issues. A highly unprofessional company to say least.
The email address of techm office is: [protected]@techmahindra.com