HCL Technologies — Issue with data on relieving letter & experience letter

I'm an Ex-employee, my employee ID is 51774315
I resigned and left HCL on Apr Jan/2019 after informing my HR. I didn't serve the notice period of 3 months as I was on bench.
After some time of leaving the company, I got mail from HCL that I needed to settle my dues by paying the notice pay recovery amount to them which I am ready to pay now but I need correction on my experience letter and relieving letter portal is showing my last working day as 22-Feb-2019. I need that to be 22-Jan-2019
I've been trying to chase HR to correct my last working day on the experience letter, but they are not responding.
MY HR left the organization he gave me contact no of other HR
My point of contact for HR's - Rohit.[protected]@hcl.com
Kindly help me as I need to show this experience letter ASAP to my new employer or else, I'll lose that job opportunity.