Prodapt Solutions Sr Software Engineer interview questions

There were 2 technical interviews, which went well. HR round was salary negotiation round where in I didn't get my expected CTC . Then HR said via call that I will send offer letter but you resign the current company immediately, but I wanted official offer letter for confirmation, then they sent a mail saying I have been selected with CTC info but it didn't had offer letter but said to resign current organization. So I again said that I can't accept without offer letter, then they rolled out offer after 15 days, by then I had got offer from other companies with better opportunities, when I rejected the offer of Prodapt the HR behaved unprofessionally taking the offer declination personally saying you used my offer to get other better ones, you shopped my offer, where in I had not received the offer letter of Prodapt at all when I got other company offer, and with rude behavior saying don't attend interview if you are not interested. Which made me feel better for making right decision for not joining this company. Common man be practical and grow up, maintain professionalism