Legal notice from employer what should I do?

I join a company with 12 months agreement and 3 month notice period , where i worked 2 months 21 where i was not a permanent employee i m probation period. I have medical issues my condition was critical that time i take medical treatment that time doctor said to me that you don't sit continuesly on chair, i talk to my team leader and told my situation and he told me that we can not give you 6 month month so i told them that i can not continue the office i that situation but they didn't suggest me what to do. After that hr call me and i also told about my medical condition but they continue mail me and i also replied what is my situation on mail and also send all medical documents along with medical certificate but continue mail and give harrasment mail that if you didn't come to office we will take legal action on you than i visit to office and meet hr department, they took me my card and meeting with legal department and said that you are now absconded from our company i showed my medical documents and they said authority is not available this time we will call you when authority is available but they didn't call or inform me and send legal notice please tell me in this situation what should i do ?