Customer Service No Response

I have had the same problems with this place as I have called 5 times to cancel my order and they keep on sending me boxes week after week of posters to which I am returning to them.  Can anyone help with this?  I do not know where to go other than Better Business Bureau since this place has no e-mail address and they do not answer the phone when I call so I have left 5 messages explicitly telling them to stop sending me these posters now.  I have alerted my credit card company so what else can I do??  Thanks for listening.  Diane McNamara