Henkel Internship interview questions

I was first asked some general questions such as "Tell me about yourself?", the hiring manager also introduced herself and the job position. Then I was given a short case study. My overall experience from the interview was very positive. However, they took so long to contact me back. They had promised they will tell me their decision in 2 weeks time, and that took 4 weeks. Given that I applied for the position 1.5 months before the interview that was a very long process. The HR didn't respond to my follow up email.

Actually it’s not that professional . The interviewer also the manager asked me to phone him at a time. However when I called him he refused and texted me “call you later” . I thought later could be 10mins or within half an hour. Even worse. I waited over 1 hour ... And we finished the interview in 15mins because it was close to the off work time.