Edunext Technologies Software Developer Trainee interview questions

At Edunext, there are three rounds of interviews: the first is a written test, the second is technical, and the third is an HR round. I cleared the first round and was called for the technical interview. First of all, they called me at a certain time, but my interview took place four hours later. In the interview, they asked questions related to strings, arrays, and the collection framework, which I answered. After that, I discussed things with HR, who asked if I could join from next week, and I said yes. HR then mentioned that they would call me, but I never received a call. When I followed up, they said that the fresher positions were filled, and I should try again next time. I don't understand why they conducted my interview if the fresher positions were already filled. It's a very poorly managed company.