Old company on verification by new company mentioned wrong information

Hi Mr Mathew my name is anchit I resigned from a company and was serving notice period by didn't serve the last three days of the notice and requested for a three days early exit to which I wrote a mail to the HR too and HR advised to write another email stating to mention that today will be my last day to which I did and in return and he accepted and wrote a email back and after 45 days I got a experience letter and my full and final settlement but recently I joined a company and during background verification with the previous company they mentioned I was asked to leave... I went to the hr for my previous company and they said they cannot rectify this... Can you please suggest me what action should I take next?