bogus charges

When I bought my computer years ago, Best Buy installed that trendmicro anti viurs. The following year I renewed that online, and had nothing but problems with it. A year later, I cancelled it and have had 3 charges over three years,1 for $169, and 2 for $39.95 which I disputed with my ccard company and they took care of it, but yesterday I had my card cancelled so this would stop. I was told by my ccard co. that these people play around with expiration dates on your card until they get a hit and they don't need that 3 digit number on the back of the card, that does change when your company sends you a new card with a new expiration date. This company doesn't ask for that 3 digit number and so they can continue to scam us. The only way to stop them is a to get new card.