written test you get a call from hr to come for tech interview and after that no response from the company after writing so many mails to hr what happened god knows

Had a call with HR manager and he sent me to fill basic HR questionary. After a week I was scheduled to have a call with Dev Manager. Had a talk with him about my experience, he gave me several problems about probability and after talk I got pre-interview questionary about math, quantitative analysis, sql, financial analytics and scripting languages. Then after about a week I was invited to face to face onsite interview - had a short talk and then everything repeated - was given another 1 hour questionary examination about math etc. Then I was given 15 minutes to prepare a presentation about something technically complex and Dev Manager invited Project manager and QA Manager as interviewers. The whole onsite interview lasted about 3 hours.