Got Terminated for No reason

Dear Sirs, This is Yogesh Kashyap from Patiala and I am here to ask for some advice regarding my job. I should say Ex-job. Till yesterday I was working with a Non Banking Finance Company named Supreme Housing Finance Ltd. I had revently joined this company as a senior Credit officer. I was on a probation period but company didn't issue me any appointment letter. I asked for the same many times, but to no effect. As I was got hired for Credit Management and processing Loans, it was not my duty to generate leads and bring loan applications (Marketting). The company had hired a Branch Sales manager and a sales officer for this marketting purpose. A Senior Manager was also about to be hired but at the last moment, he denied from joining the company. As the Senior sales manager were in good terms with Branch sales manager and sales officer, they both resigned after taking one month salary. After their resignation, the company's HR started Harrassing me by stating that you are not doing any work. I asked them many a times that my job profile ia to process files and how come would it be possible for me to process anything if there would be no sales person for sourcing the loan applications. HR and seniors continuously asked me for putting up a resignation to get immediate reliving without any compensation, to which I denied. I asked them for some time to find myself a new job or some compensation but they didn't agree. After two days they sent me the termination letter on my email id mentioning the immediate effect. They ahve mentioned the reason as "Non performance" on the termination letter which is not genuine as per my job profile. HR also told me that the company is no longer interested in making any Home Finance business at my location, so they are shutting down the branch. I asked them to shift me to another location but they aimply denied. Now I 'm confused about the situation, as I belong to a mediocre family and me and my brother are the earning pillars of my family. Please suggest what should i do now?