Can An Emplyer Blacklist The Emplyee If He Absconds?

Hello,My name is atif,i was selected in an interview in a well known Bpo,which is registered with Nasscom.I have compled my joining formalities and got the appointment letter,but my training was not started,the next day they called me an asked to sign a bond with them for a year,but due to some reasons,I refused to sign it.Then they started forcing me to sign the bond.they said that we have appointed you for that,your joining is done,and nw i have to sign it.and i will not sign it and leave the job,then they will blacklist me.but i didnt sign it,and left the premises.they again called me,to come and sign it,or they will mark as abscond in my data base and Nasscom and blacklist me.but i dnt want to go there.
...so please,anybody help me out with this.Can they abscond me or Blacklist me,as i have not signd the bond..will it have any effect in my further jobs and career??

If i would say yes, can you please let me know who will you perform this task? What procedure you have and what you can do to declare an employee as blacklist who have absconded?