DSS Inc Subscribed, Did Research, Discovered Scam, Now what? Pilot Point, Texas

I was just recently bombarded by two young salesmen from this company.  They were fast and smooth talkers and I was immediately confused and convinced.  I ordered a subscription and wrote them a check.  Immediately after this I did some online research and discovered it was all a fraud.  I have mailed the cancellation form.  I also plan to cancel the check and have notified my bank of what happened and that their company policy says that if the check doesn't go through that they will debit my account the amount of the check plus a fine.  Should I go through with the check cancellation or will this just cause more trouble for myself?  Has anyone successfully prevented this company from taking any of their money after falling for the scam?