Breaking unreasonable employment bond

Hi, i'm currently working in a software company as a software developer..i have signed an employment bond for 2.5 years with this company when i joined there as a fresher..which stated that if i break the bond i'll have to pay 2.5 lakh rupees..it is an year since i joined there..i was given a training for 15 days in php but i joined the Rubyonrails team..so had to learn RubyonRails my self..they pay me 10000rs per month n i dont expect them to give me much hike..as from my seniors i came to know they just give a hike of 3000rs..so even after two years i ll be paid below 20000rs per month..and i have to work day and night like other employees..also i dont have much opportunities to learn much here since i work in a product which is useless and the company in least bothered about it..so if i stay here i will not gain in anyway..neither money wise or knowledge wise..so i will be wasting my time if i stay here more..i would like to learn n earn more..i come from a poor family n have a tough life..i was hoping to leave this company peacefully stating some medical reasons..what should i do..please help me..