Notice U/s Negotiable instrument act on resignation from the job

My son had resign from his job without serving notice period because of harassment and humiliation in the office by its owner. The company had taken cheque of Rs 40000/- as security and got signed Bond. After resignation we stopped the payment. As such, the cheque was bounced. The company has now served the notice u/s 138 of Negotiable Instrument Act. As he had resigned due to harassment and humiliation and not because of any other reason. In fact, the company could not provide the good working environment in the office. He was in the job only from 22 Sep 23 to 30 Oct 23 The following points were mentioned on RS. 100/- stamp paper of Bond. 1. 2 months notice period 2. Details of two undated signed cheques 3. Those cheques would be returned after 11 months. The company didn't provide the copy of this Bond, saying that it was confidential. Your further guidance is solicited.