Synergy Infra Consultants interview questions

I interviewed for Junior HVAC Design Engineer. The First Test was CAD model test where in, I was given a Part Drawing and was asked to draw it and then I was taken the Technical interview by Technical staff and HR. I didn't do well in the former one but have answered almost all the question in the technical round. The technical staff told the HR that i can be considered as a freshers. The next day i got a call that i have passed the test and offered me the job with a less salary than it supposed to be for a fresher in the respective field, with a condition that i have to sign a bond for two years. I have said yes to everything and asked when will i get the offer letter. The HR said it will be mailed and i waited for the response and after two days i called them regarding the above but they didn't answer the call.