SellerApp Backend Developer interview questions

I was contacted by Dilip Vamanan on WhatsApp. He did not even tell me his name. I forwarded him my Resume and he was very much interested due to the work I had done. So, he called me with a phone number which was different from WhatsApp number assuming I knew his number. No introduction of himself, I did not even know he is from SellerApp but as I had just applied for a single company I figured it out him to be Dilip Vamanan. He asked my detail and wanted to schedule the interview on the same day, but I asked him to schedule the interview on the next day morning with which he was fine. So, the phone call interview was scheduled for October 17, 2019 at 9:30 AM. As there was no call from him, I waited till 9:40 then contacted him on WhatsApp just to know that he was in a stand-up meeting and cannot conduct the interview. He rescheduled the interview on Monday i.e. October 21, 2019 at 9:30 AM Again the same thing, no contact from him till 9:30 AM. I again contacted him at 9:40 AM on WhatsApp. He called me around 10:00 AM and told me that they had the interview drive on Saturday in which they have selected two persons. He told me we can go ahead with the interview but mostly we have selected those two persons. He did not want to waste my time by taking the interview as the persons were already selected. I told him to go ahead with those two guys. But, can't he understand he had already wasted my time. The thing is this is very unprofessional behavior. For the interview on October 17, 2019 I guess his standups are ad hoc that he did not know earlier he will be having standup on October 17, 2019 at 9:30 AM. Even if ad hoc, a founder of the company should be professional enough to inform the candidate for unavailability and it would have been perfectly fine. But stating the reason only after contacting him is not what professional persons do. Again, maybe his interview drives are also ad hoc that he didn't know till Friday that there will be an interview drive on Saturday (Really). If he had already selected the candidate on Saturday, it would have been professional enough to let me know that I won't have the interview on Monday. But, after wasting my half an hour waiting in expectation he called me at 10:00 AM that even after messaging him on WhatsApp. It was an overall very bad experience and I do not know how things will be in his company. Are they really this ad hoc?