CENTRAL COAST NUTRA INC Acai Berry Have Now sent me to collections because I cancelled it and credit card cancelled Internet

I ordered a sample of the acai berry from Central Coast Nutra.  I was unaware of the fact that if I cancelled the item before the 14 days was up and did not send back the unused or used bottle to them that they would keep trying to charge me. 

I have been notified by e-mail from that company that they are taking me to collections and that for some reason now I owe them over $150.  I cancelled and also cancelled my credit card because the bank told me they were having a lot of trouble with this company.  So on the notice that I got from Central Coast Nutra recently it shows that my credit card was declined and I never did receive anymore acai berry except for the trial which I paid for.  It was only shipping and handling of $4.95. 

Now I don't feel that they should be going after me for anything else since I did cancel but I do not have anything to show for that because I called and cancelled.  The person on the phone never told me to send anything back.

What can be done about this.  Now they are trying to call me.