mc Group interview questions

Was invited for a face to face interview at their office. 3 people from HR interviewed me. Lasted for about 15mins (could have been online). They got back to me in 5 days asking to do a face to face interview with their Director on Sunday 5.30pm (SUNDAY). A few hours later, they email me saying they made a mistake and rejected me.

Fast to answer and schedule interviews. Interviews by HR, CEO, team members, etc. Most interviews are in person, in the office- people are nice. Some interviews on sundays. The majority of the process was scheduled quite fast and during a couple weeks.