Mobile Programming IOS Developer interview questions

The Interview was average. They have a panel of around 3-4 people for half an hour interview. After the interview I got a mail from HR as I got selected and there will be no further rounds. Then they share me 2 documents files to fill, That takes almost 2 hours to fill all the details. I shared the details on time then I Got a call from HR, So I gave them a tentative date of joining. Thats it. Then there is no revert from HR after that. No offer letter. HR is not picking my phone. Not Reverting on the Emails. Worst experience I can ever have in my life. I mean HR's are this much unprofessional in the company that they are not even sending the Rejection mail or telling the reason of rejection to the candidates.

Interview Process happened when the hr called and it was a meet call interview with on of the developer in the company it was nice talking with the interview has good knowlege of ios and interview went well