Absconded

Hi, I was working with a company for last one year. As per the agreement, I had to serve a notice period of 1 month. I served notice period for 18 days. I fell ill after that and couldn’t show up to work.. I asked my manager about leaves and he approved 3-4 days leave but I still couldn’t join the company because of my health issues. My manager told me that he will mark me absconded. I emailed my managers and HR stating the objection health condition along with my medical but no options like buyback, earned leave deduction or early release were given to me. On the very last working day, I went to the office, logged in and provided all deliverables.. after 20-25 days, when I emailed HR about my relieving and settlement, they refused to give any of it saying that I am absconded. Can I be marked absconded after being in constant touch and even supporting my team from home ? Can an absconded employee Login and work ? Does an employee required to complete the exit formalities after being marked absconded already. ? Can I file against my employer and HR for taking 3 months to not provide me details and also not provide me the reason of absconding and informing me that I was absconded until I asked them about my relieving letter ?