What is the procedure with regard to unfinished thesis if I am terminated from the program? I am an international student and was enrolled in a PhD program for the last 4 years. My GPA is above 3.8.

I was recently given a termination letter(without any warnings) from my department regarding my PhD program. Apparently my termination is because I missed a deadline for an article submission. I am surprised as I was not given probation for even one semester before termination. It could be because in the last 6 months my progress on my thesis was slow because I was busy with a few personal commitments.
i was getting married and had a couple of unexpected deaths in the family. 

EDIT: "The deadline I missed first was a mutually set one to review the final draft of an article to publish. I missed it by more than 10 days as I had a death in the family. I sent the final edition of the draft 5 days before actual submission date for the journal. But got no response. I missed the submission date as I had no feedback from him."

I am in the last year and finishing my data analysis. I was outside the US for my research and my I-20 expired last week and now I am stranded outside the US.
As it is the summer vacation, the staff and my adviser are unavailable on the phone.
I got a reply to my emails as follows:
For the i-20, since you are currently no longer in the program. I cannot complete a graduate student program extension form for you. 
I wish it had turned out better for you. I am available at any time to talk. 

But the office line is still under answered. I don't have any other number. I have emailed him asking for a time and number I can contact him. 
Weirdly got an email today saying let's talk on 17th June. The other members havnt responded. 
An old student of the my advisor told me something similar has happened before where a student was told to look for another advisor by my advisor. But she was in her first year. It was because he felt the performance wasn't up to the mark. It was also very unexpected as he was always very cordial with her too in team meetings and department meeting. The girl took up another professor and completed her PhD. 

What options do I have?

Should I wait to get back in contact with my department or should I look for other universities and programs?

What happens to the data I have collected? As I was outside the USA during the data collection, I was not given any stipend while I collected the data. Do I have rights on my data or does my adviser or does the department? The data is in audio format collected by me using a set of guidelines created by me but approved by my adviser.

I might be getting ahead of myself, but I am, to say the least, feeling panicked right now.

UPDATE Jan 2020: The advisor never explained properly, but 5 years down the line I understand what happened. My advisor wanted to leave the institute. I believe his contract/commitment made it impossible to do so while I was a student there. He did write me glowing recommendation and helped me secure a good institute in my own country. Due to the setback and credits not transferring, I had to "sit" through some courses but I will be defending my PhD this year. In the mean time I have written chapters and articles with my new and my old advisor. The old advisor runs his own research institute. The data is mine to use without issue.

I do not like being in the dark and my life partner helped me live through those times. What I will say is that power dynamics for an international student make the advisor more powerful than should be. And without an option I had to spend more time than I should have to complete an already long PhD. 

Thanks for all the responses. As you can tell I opened this account and have worded everything to ensure that there is anonymity for all involved. The advisor is highly regarded in my field and his willingness to work with me is a disincentive to reveal/smear his name. Now that he has a private research institute without any international students, I hope the same will not be repeated with others.
Departments generally do not terminate PhD students without letting the student's advisor know in advance. The fact that your advisor has not responded to you for 3 weeks, suggests the possibility that he/she is ignoring you. This is reasonable behaviour, if in fact your advisor was behind your termination.

As you are not currently in the US, you need to call your department chair and/or the chair of graduate studies and figure out what is going on. In my opinion, it is too soon to look for a new program or to start really worrying about your data.