No answer, no cancelation, no refund

I booked a reservation for march at the Sandals Royal Caribbean ate the website. It was a free cancellation fee. I tried to cancel, writing at the website, sending emails for two different address and by the phone. Yet, I did not receive any answer, and yet they tried to charge my credit card.
This happen at January 27 and 28, and I still didn't receive any answer.
I want my refund of the $400.00 they charge at December 31, 2016.