Not issuing academic certificates after verification from company

I am working as a web designer in a company. I signed a bond for two years and at the time of joining they asked for my original certificates for verification after that when i requested for my certificates for taking passport. First they asked for blank cheque when i agreed that then they are asking for blank document with my signature. After i agreed to give they changed their opinion again they are telling that they want 1 lakh as money. I told them i will return the certificate after the passport verification. One more point that they deducted my salary for PF but the account number which they have provided is not existing for me and some of my colleagues . In my bond which is in a white sheet paper it is clearly written that we need to submit only the copy of original certificates and they need the certificate only at the time of verification. I have also a white sheet with there seal saying that they have received my so and so certificates. I have no intention to break the bond but now am afraid to work on this company. Around 6 to 8 employees have the same complaint rest are also having the same problem but they are afraid of these management. Someone please help me and kindly suggest some solutions