Signed 1year bond with current company

Dear Sir/Mam, I joined a company on 18th July 2017 as a HR in hyderabad. I signed 1 year bond with them and gave my B.Tech certificates. I got into a bike accident on 16th April 2018 and took leave till 6th June 2018. I have joined again on 7th June 2018 and still working here. I gave my resignation on 23rd July 2018 and they told me that I should serve notice 30 days along with the break i took because of accident(52 days). My last working day given by company is on 15th October 2018.If I break the bond I have to pay 30,00 cash to get my certificates back and serve 30 days notice which is practically hell. They are torturing me because I gave my resignation. Since everyone is leaving and there are more empty sets in the office, my boss gave an offer with 5000 hike per month and I have decided not to take it. Because I know that I cannot go through this hell for 5000 extra money. The moment I declined the offer, they made me target again. No one has stick with them till 1 year. They ask ask us to work from 9:30 AM to 8:30,9:00 or 9:00 PM. Only half n hour break for lunch that too we have wait till they give us permission to eat. Our regular lunch timings are done at 2:30 or 3 pm. As a HR we have to make calls to the candidates and they want us to be on calls continuously from morning to evening. I cannot go through this anymore. Please help what I should do to get back my certificates without paying them money because I have practically finished 1 year and they should be giving back my certificates to me.