BrainScale interview questions

Went through three rounds of interview and got selected, even submitted the documents for verification, Interview process took almost 45 days, and I was told that they will be providing offer in a week but no replies till now, after that I have accepted an offer from other company. The fact that they took 45 days for 3 rounds of interview and even after getting selected offer was not given is unprofessional.

Had 3 rounds One with the hiring manager(US); Panel from India(telephonic round from a PM); The third round was from the Program Manager(Canada) Self Introduction; PMP-based questions, behavioral scenario questions. It took almost 3 weeks to finish the process and release the offer