Resignation - continually taking follow up with my manager but he didn’t inform to HR

Hi, I have resigned from my previous organization on 24 hours of notice because I was unable to serve notice period because of health issues then after all these things I have informed my previous manager so he said to put a resignation mail to him and keep cc to HR so I have done the same I was continually taking follow up with my manager but he didn’t inform to HR at the last point he told me to call HR directly now HR is saying she didn’t know anything and also manager didn’t inform her anything but I have kept HR in Cc but she didn’t inform me my resignation was accepted or not and the manager said that he will handle now the manager is refusing that he knows everything so that's why HR not giving relieving letter so what can I do?

Are you expecting you will get a relieving letter when you left an organisation without notice?
It is possible your manager wanted your cooperation with return of company assets and files, etc so he said ok at that time.

For the rest, your only option is to go and talk to them, and see if you can get the relieving letter amicably.

Since we do not know the company and its internal dynamics, I don't think anyone here can help you