Greytrix Web Developer interview questions

I attended an interview two weeks ago and successfully cleared all four rounds (two HR rounds, one technical round, and a final round). The entire interview process spanned two days. After completing all the rounds, they assured me they would contact me, but I did not hear from them. After waiting for four days, I called them and was informed that my application was on hold. Seven days later, I called again for an update, and they told me I was not shortlisted. The entire process took two weeks, and ultimately, I was not selected. The management here seems to be inefficient, and I was not given a proper reason for my rejection.