Company full and final settlement amount after absconding

Hi, I have joined a company as Tech Lead in 2019. But I have been forced to work on different skill set without any trainings and I have been asked to extend my working hour daily. I have companies the same to company management (in the email - I have a copy of this in my gmail account) but there are no action taken from the management. After I did all the try to fix all the concern I was helpless to abscond from the compnay. But I am continually getting email and letter for the recovery amount. Also said that to provide amout + 15% interest on each year till now. Whereas there is a clause mentioned in the offer letter below - (d) Unauthorized absence or absence without permission from duty for a continuous period of 7 working days would make you lose your lien on employment. In such case your employment shall automatically come to an end without any notice of termination. If above paragraph(d) mentioned in the offer letter then why to serve notice period. Moreover companies cheated with me . Please advice.