RNK Communications review: The company has totally disappeared, and is un-reachable. 1

I have bought about 30 international calling cards ($5 and/or $10 each) by RNK.
I have been making telephone calls with the cards.
All of a sudden, the cards stopped working. The company could not be reached. Supposedly, they went out of business overnight. Without any prior notices.
How can I receive the refund of the money on the RNK cards which I still own?
Thank you!
Simon Zaslavsky
Tel.: [protected]
My e-mail address:
[protected]@yahoo.com