Emplyment bond with certificates and demanding money.

Hello sir/ madam, I joined a company in Chennai 4 months(6 month probation)before and signed a mandatory bond with them for 3 years to work in the company submitting my engineering and plus two certificates. But the nature of work is pan india travel, and im not able to adjust to food in different rural places and was hospitilized for 15 days due to food poisoning. So i want to resign. Now they are demanding 4 month salary back in name of training but i wasnt provided any training per se. Only internet connection and worked with senior and learned by self effort and provided value work to customer. How should i proceed? Can i get legal help