Siemens Full Stack Software Engineer interview questions

Was in touch with two recruiters for the same position. I met one of them at the NSBE conference and had an interview at the conference. The other phone contacted me through email to schedule an interview. Both were introductory and of the same nature. They said they would be scheduling interviews but never did. Its been one and a half months since. I tried using the same link I use to schedule an interview. The interviewer had the time to respond with "Just a heads up, I am unavailable during the time slot you picked", but never had the time to update me regarding the status of my application. Why do they waste people's time like this? Terrible.