lucid im assuming you live in the US, so the easiest way around this is to use a store with almost no cameras/none and a known "short" time span that they save their video. then just use search engine of your choice to find a group of identity sites. some of these actually restrict themselves to law enforcement, a LOT dont. the hard part is finding two sites that let you "search" someone that allows you to get full info. ie name and SSN from one address/phone from another by SSN. you can pay for the service, but that would be traceable back to you before you get your prepaid card. the downside is that once you use these details for the card is that you have committed identity theft(technically). this way is "illegal", for a more legal way you could do something like....
transfer some money to e-banking site, transfer to bitcoins(and again depending on how deep you want to hide all this...can do several encrypted transfers, though it will take a % of your cash each time) finally transferring back to a "secure" paypal or other site that is not linked to you at all(proxy's etc). then using THAT money to either flat out buy what you want online, OR using that money to buy prepaid cards purchased by others. this way IS legal, just expect to spend 10-20% extra on the items you want.
I also feel it should be noted that even using a "secure" prepaid card is no guarantee because of security cameras. So if its something you feel is a really sensitive purchase, take into account the logs/recordings they keep as well.
One last note: if using the second method you ALSO need a secure PO box or similar to drop the mailed card too. otherwise it leads right back to you anyway. Unfortunately in an information society it gets harder and harder every year to move money around secretly/buy without a record. THAT being said if your purchasing from a B&M why not use cash? untraceable and no additional costs, just take cameras into account. then for online purchases that are sensitive just wash through paypal, bitcoin, paypal for a relatively secure transaction. (though again for that you need a box to drop too, or their logs of the purchase will be seen to have gone to you. obviously get the box on the same washed money)
well hoped that helped...