Netlink QA Automation Engineer interview questions

Interview started one month ago and there were 2 technical rounds 1 VP round and 1 HR round. I have cleared all rounds of interview. But when it came to release offer letter they asked me to join early however I had clear discussion with the HR about my last working day in current organization and it's just one week away. Management should have clear criteria before contacting any candidate so that he/she don't get disappointed after one month of long process. Thanks for ruin my time. Worst experience ever.