Fullerton Health Senior Software Engineer interview questions

Interview was very smooth and simple with hiring manager. After that HR informed that I passed and they would like to offer via call one week later. He said company will apply EP right after I accept their offer. But when I told him I accept offer, he hasn't sent me offer letter yet even I tried few times to message him. And then he told me I have to wait more than 3 weeks because they couldn't apply EP this moment. And still no offer letter sending. He hasn't say sorry about their issue. I already rejected another offer when I accepted with them. The company is 10 years old but HR is really bad and unprofessional