How would people suggest changing it?
As others have suggested, it might help to add a little explanation of the secondary market, saying something like: "Any gift card you buy from CardCash is something CardCash bought on your behalf from someone else. Unfortunately, in today's day and age, there are dishonest sellers out there. In order to make your transaction more secure, CardCash will guarantee the value of the card for 45 days. If something went wrong within that period, CardCash will either have recourse with whomever they bought the card from, or stand behind it themselves. After 45 days it is impossible for CardCash to guarantee anything about the Gift Cards you bought from them."