Tech Mahindra Frontend Developer/UI Developer interview questions

The interview was scheduled directly through Tech M (Pune). I asked them about the interview process before going and the assured me that all the rounds will get cleared on one day itself. So I went there on a public holiday for an interview . Both the technical rounds were technical - telephonic and the third round was HR Face to Face. The HR discussed the salary, showed me the salary breakup and asked me to mail all the documents after I filled their employment form. Its been 3 months now still have not got any offer letter nor a mail informing the status. I had heard about this kind of behaviour from Tech M before but I still cared to appear for an interview , that was my biggest mistake. Advice to all : please dont waste your time / weekend on this.