Tech Mahindra — did not get the uan number from a company

Address: Pune, Maharashtra, 411048

I was an employee to aditya birla minacs pvt ltd. I was working there since september 2015 to april 2016. Was forcefully absconded from the company as i was on leaves due to medical emergency. They did not give me any documents for pf. Now the company is been taken over by concentrix. When i called to ask for pf withdrawal, they asked me to fill it online. But online filling needs uan numbee which is bee not provided to me. No one is willing to help.