Xavient Senior Software Engineer interview questions

Two rounds, first was telephonic and second was face to face at their noida office. After giving a fairly satisfactory interview, I was made to wait for 2 hours in a cabin. Finanlly an HR came and discussed about my profile and salary expectations. He said they have a positive review from the interviewer and would forward me the offer letter through mail. After this they never called neither picked up my calls. Highly unprofessional behaviour.