Qualcomm Sr Engineer interview questions

Technical Interviews are good, Hiring manager, as well as interviewers, check different skillset of the candidate. But The HRs of this company are very errogant, ignorant. After the verbal offer I tried to contact them through Call, Mails, text, whatsapp But they are unreachable. They don't want to communicate with the candidate. Even after the offer letter I mailed them to give some, I want to talk to talk about something over the call. But they don't have time and will and discuss anything with the candidate. Very bad Experience