Cognizant Technology Solutions — Incorrect Service letter

I left cognizant 3 months ago and my last working day was 30th March. It was a one day resign because of a family emergency as they were calling me to office in covid times and said I have no option. After giving my resignation it was a long thread of emails going with my HR, separations teams and exithelpdesk of cognizant. My HR Informed me that all approvals are now given and I might need to pay out for the 2 months notice period which I did not serve. I was completely ok with it and requested team to proceed with it. The team took very long to respond, as today is 25th July and this was going on since 30th March. After so long I received incorrect service letter, with last working day as 28th May. I again dropped email to [protected]@cognizant.com, this hrss team never responded and the exithelpdesk is not able to help. I need help with correct service letter.