SAP Development Associate interview questions

Extremely unprofessional and dishonest recruitment process, I was verbally offered the position and then the manager ghosted me for a month before sending me the rejection. It cost me other good positions, as I verbally accepted the offer and had to decline the others. The interview spanned two stages, in the first stage, it was a chat over Skype with the hiring manager discussing my CV and past experiences. The second stage was an on-site interview with system design questions and solutions. The hiring manager made a verbal offer on spot and said that he's initiating the HR hiring process. There was another email later containing the project brochure and a message saying "looking forward to welcoming you on the team". Then the manager disappeared, after emailing several times and I got a very cold response months later, saying that the HR lady would contact me "in a few weeks". The HR lady then sends me the standard rejection, saying that they're not proceeding with my application.