What to do when finding difficulty in resuming study? Suppose, I completed two semesters and left a university two years ago. I want to resume my study again.

I e-mailed a specific guy in the faculty/department/institute. I need a readmission paper from that guy to resume my and he never responds to my e-mail let alone other guys who are in the upper part of the pyramid. My time is running out very fast.

What is the best thing I can do in this situation to get things done amicably?
Invoking Occam's razor here, the likelihood that someone is out to get you personally is probably lower than the likelihood that someone is just being lazy and/or slow to respond to email. Before lawyering up—a serious escalation—consider calling on the phone or even visiting the administrative office to see what's up. (I didn't get from your post as to whether you're in country or not.)

Regarding your comment about you having left the country—"absent but failed to let the office know"—that may be a serious offense on your part. If you studentship was terminated there's a good chance that you violated one of the policies of the university with your unreported leave and they terminated you for that. Email is easy to ignore; use other methods of communication to get in touch and verify what happened.

Lastly, make sure that someone is checking your mail at your registered place of residence in the country in question. If you're out of the country, they may have been trying to get in touch with you but you aren't aware of it.