Employment Bond & Contract

Dear Sir, I need your suggestion for my case. I have signed bond of 3 years with organisation with bond break amount of Rs. 100000. I had little restricted to bond as it was my first job and less serious about bond in joining days. They have signed bond with blank cheque. They have not shared agreement copy with me. After served for 2.2 years, In feb 2016, I have officially resigned by mail. They accepted my resignation orally. But they forced me to submit leave application form of 1.5 months and told me that they will relieve as soon as I submit bond amount. They told me to write date on cheque of 30 april 2016 with sign and forcefully I wrote it. They have hold my last month salary. I have sent mail on 18th May 2016 for not to submit cheque and give idea about bank account is inactive. I mentioned to destroy cheque at your end or send back to me via register post as it is security deposit cheque. Today they have sent notice from lawyer to pay cheque amount + taxes within 15 days and mentioned clauses are 138 & 420. They have submitted cheque on 17th May 2016 without intimated to me. Please suggest me your views. What are the labour laws that will save me. I am not in position to pay bond amount. Thanking you in advance for your kind suggestions.