I take it you have never tried to use the support system of many of these services? Yeah, you may sometimes get a good rep that will actually help you and refund you. More often times than not you are forced to jump through massive hoops, auto replies, no help, etc. to the point that you have to do a chargeback. Also, chargebacks are not always a guarantee, VISA (or whoever) does their own investigation to make sure you're in the right, so you would only likely go that route when you're confident that the service is in the wrong.