Dynatrace Javascript Developer interview questions

I applied online and got an automated response (as usual on lot of companies). A couple of days later someone from their recruitment team contacted me by email saying they will review my application and will contact me if there is a good match; in the meantime, they want to propose me to make a call with them in order to clarify the Job Role and introduce the company. Attached, was a link to book the call. I found that great and replied appreciating this and kindly asking if they could sponsor my visa. I didn't get a reply. I booked the call for following week. I've never got a reply from them. I was doubting if they would even show up for the call. I asked in advance pemission on my current job for that. One hour before the booked time, this person (who contacted me by email) visited my LinkedIn profile. I imagined this person would be aware of the interview and will appear. Never did. I sent to this person emails and wrote through LinkedIn (apologizing for using it to ask that) but still, never replied. I would have understood if they didn't like my profile, or could not sponsor my visa, or anything, but I would have liked to have a reply at least. I ask for permission on my job, I prepared, I was excited, I spent time on it. I know this person may not represent the whole company of corse, but I really just wanted a reply and I never got it. Dissapointing.