Employer not releasing PF and salary after I resigned during probation

As the title suggests, my ex employer is holding back my salary for 16 days along with my PF amount I earned for 3 months and 23 days (I joined in the fourth week of March and resigned after the second week of July). My monthly salary was ₹21,000 INR after cutting ₹3,000 for PF and ₹1,000 for gratuity (awarded after 2 years of service). When I joined, I was made to sign a contract wherein it was mentioned that the office would be making 'considerable expenditure' on me and will be giving me training. Also that if I leave before 1.5 years, I am required to pay the ₹50,000 because of the before mentioned expenditures and training. While working, I was not giving any proper training (was asked to just go online and see what it is that I needed to know to work there, and if I had any doubts, every senior would say that I am busy) and the laptop I was assigned would keep hanging to a point that a work of 30 minutes took a few hours to complete. I would constantly bring it to their notice but they didn't do anything about it. Now because I resigned before 1.5 years, they are holding my salary for 16 days and the before mentioned PF amount (they havent given me my PF account number). They said they will sue me for not agreeing with the contract that I signed, but they themselves didn't fulfill the reason for the bond. Then why should I pay the bond as stated? How should I proceed forward? What procedure should I follow to get my salary and PF amount?