First Republic Quantitative Analyst interview questions

I first received a pre-screening of SQL and R questions that they gave me 7 days to complete. Once completed, I had a phone interview with the hiring manager which then lead to an in-person interview with the team. The interview consisted with one on one 30 minute interviews with each member of the team asking questions about my expectations and various SQL and R questions. The hiring manager said that I would get an update in about two weeks. After more than two weeks I emailed the hiring manager numerous times to get an update. He told me that they are still interviewing other candidates and will let me know in another week. Another week goes by and nothing from the hiring manager. I recently received an offer and emailed the hiring manager that I need a decision. He emails me back a short one-liner stating I should accept the offer. The hiring manger is completely unprofessional and I have had a similar experience with FRB in August where they gave me a verbal offer then totally ignored me for months. I think this bank is very unprofessional over all and I would never consider interviewing or working with them ever in the future. They wasted a lot of time and are completely inconsiderate and unprofessional.