I attended three interviews in succession and got through all of them, job role specified, salary negotiated, etc. I was promised an offer letter through email the very day of the final interview. It didnt come. The HR said they have to get the MD's approval. Another day passed. It didnt come. When I tried to call, HR says they will send it soon but haven't sent it yet. It has been 8 working days already. What should I do? Give them a week and then call up? I also dont want to keep calling and show that I am desperate.