IBM Software Development Engineer In Test SDET interview questions

A recruiter mailed me informing the job opportunity. After registering in the company website, they have sent a hackerrank test which I cleared. Next day I received a mail from recruiter saying that tomorrow will be your tech interview. I have waited all the day for the mail but they didn't send any info. Later I got a mail to finish one cognitive ability test. The next day one hr contacted me to know my availability for tech interview I said 3pm. They have sent a link for 4pm. And they cancelled it without informing me and scheduled to next day 10.30am. Another hr contacted me saying interview will be at 4pm and ignore the mail from the other hr. Later both cancelled it. I really have no idea, why they wasted my time. I have spent almost 4,5 days for this, totally wasted.