cheque and employment bond issue

i have joined an IT company in last month..at the time of joininng company has taken blank cheque as my employment bond..for 1year....
they have not given me any appoint mentletter to me......i went to company for 2days ..after that due to my health issue ..i have under went surgey........
i have also informed to my concerned HR about my health issue ..and also said that i have take rest for 2-3mnths.......i have also enclosed all my surgey related document to my HR through mail...
they are saying that they cant hold.my job for 3mnths.....i also said them that i will come after 
3mnths.......they are not accepting it...they are saying that they will not wait for 3mnths .......

plz tell.me.what will be the consequences to be faced from my employer side...
i have done stop cheque payment from side..plz.help me.out