Service Agreement / Bond

When I was selected for the job in 2019, there wasn't any bond but soon after I have received the mail that I have to accept a 3 years bond agreement or 3 lacs fine before joining my current organization and I have accepted my offer letter along with the bond as there was a job crisis during that year. But now after serving there for 2.5 years I want to leave for being under paid and bad/ improper management. I have already received a better opportunity from a totally different company but my current organization is not leaving me. My current employer is asking me to either serve my remaining six months or asking me to pay my bond amount as per the bond and I am not willing to stay in my current company due to their bad management and want to explore my opportunity. Note : For working over 2.5 years, I have received my salary receipt for not than 3 to 4 times and for financial year 2021-2022, I haven't received a single receipt of my salary proof. They don't even had a proper HR department and they are threatening to sue me. Please help me and guide me to get out of my current company. I will be waiting for your valuable response.