Alef&Maqroll interview questions

1) Face to face interview with the HR. Pretty easy and straightforward. At the end of the interview I was given a sort of test with 5 questions (maybe 6) based on a case study. quite easy 2) They invited me for an assessment day:There was the same HR and 2 more people, one team leader and one trainer. We were a group of 7 people, they made us introduce ourself a little and then there was a "game followed" were we had to discuss situations. Then they gave us an object and we had to sell it to the other person. Final part it was a very quick face to face interview with the team leader and the trainer. I recieved the offer but I was told I would start in January (not in December as it was gonna be initially), fair enough I discussed with the HR that I had some prebooked fligh in december. After a week I got the offer, they called me saying that there was a change in salary, it would be more money, so no problem and then if I could step by for an additional interview as they wanted to slightly change my role. I went back again and they wanted me to "interview" with another team leader. They confirmed that they wanted me, they only had to define the start date. During the entire process told me so many times that if I accepted then please do not let us down last minute, please compromise if you accept and so on.... Well they completely disappeared. In the meantime I got another offer somewhere else and I waited anyways for Alef&Maqroll to let me know but they disappeared and never came back to me again. Very weird and unprofessional