Edom Technology interview questions

Attended 3 interview with the company and was offered for the position (via email) . However there after offer accepted, HR keep drag for the issuance of official offer and rescinded the offer after 3 weeks. The reason of rescinded was unable to process due to salary package. It's very unprofessional as if you got no budget for the salary then shouldn't offer to the candidate. It's waste of my time.