411./ca Failure to cancel service, Still billing me 5 months after I cancelled the Service (Twice in writing) Toronto, Ontario

I used the 411.ca on line advertising services for about 6 months and paid my bills automaticly using my business visa casrd number. I tracked where all my work was coming from and did not get one lead from this service. I cancelled in writting via email to my account client service rep on Jan 29/11. I received a confirmation of read from this email on Jan 31/11. They never responded. They were entitled to 30 days notice of cancelation. After two more payments were taken from my visa, I emailed the client servioces rep again regarding the orginal cancelation in Jan/11 and again got a read receipt, but no act ual response. They again took out another payment in April/11. I then changed  my credit card number and have started a claim withn visa to try to get back my two payments that were wrongfully withdrawn. Today I got a paper bill in the mail asking for the two payments since the card was changed. They are either very disorganized or are purposely disregarding my written email cancellation notices (although I have the two email read recepts to prove that they did read them). Stay well clear of this company.