Bauer Media Group interview questions

Applied for the role, had a telephone interview (1st interview) with the hiring manager and recruitment lead. I was then asked to come in and present a response to a brief to a more senior manager (2nd interview). Great feedback on the presentation, but the hiring manager felt that I was too experienced for the role and would instead recommend me for another role in a different team. A bit late in the process (two interviews so far) to say i'm too experienced, but I agreed to find out more about the other role they wanted to put me forward for. I received a call a few days later from another senior hiring manager (3rd interview). We again talked about my experience and the new role. I was told that my experience was exactly what they were looking for, and that a higher salary had been secured. I was then invited to meet the new hiring manager, and another person in the team, at a hotel for coffee (4th interview). We discussed the role in more length; they even went into detail about operational processes such as expenses budget for taking clients out, how quickly I could start, and even quite open comments about people in their team and ability (or lack of). At the end of the meeting I was verbally offered the role by both people, and that they looked forward to me joining the team. A few days later I still hadn't received the formal offer, so I contacted the recruitment lead on the delay. That evening I received a call from the hiring manager, who proceeded to tell me that he felt I was also too senior for this role, and that in fact he was 'doing me a favour' by withdrawing as he felt i'd be too bored. 4 interviews including a presentation of free ideas to grow the account, a meet and greet, and two verbal offers (across the span of 1 month), all to be told that I was too experienced. The most unprofessional experience i've even seen, and shocked that senior managers would essentially bad-mouth their own colleagues to a candidate very openly. I complained to the hiring manager who to be fair was very apologetic, and copied in her senior manager to investigate the situation. I didn't hear anything back. Beware of Bauer.