Trend Mirco security for the internet

 I did have micro trend for my internet security but my computer kept getting viruses while using this service and I kept having to put it in the shop costing me hundreds of dollars to fix it. IN Dec.of 2012 they renew my services and in jan. of 2013 I called and cancelled this service with them and told themI wanted a refund put back on my charge card. I never get it and I call them in May of 2013 and ask why and they file a notice by=ut still no refund so I recall again Nov. 2013 and was told by them that I only cancel my automatic renewal I infrom them I cancel all of trend and that I didn't even have it on my computer anymore due to their not keeping viruses out of my computer and having to keep putting it in the shop because you never did what you where to do.  They infrom me I waited to long to cancel but when I infrom them I did not they told me about in Jan2013 I never cancel it at all on the renewal so they took $39.99 from me and are not going to refund it back to my charge card. I fell the stole from me since I called in Jan. of 2013 to stop all service from the and to get a refund.