I live outside the Septa area and only use the system a couple of times each year. On my last trip the vending machine for the subway line issued me a Septa Key card, marked Quick Trip 3 places on the bottom of the card. This is my first time getting one of these. Reading the back it say only good for day of use printed on the front. I take it these are not something that can't be saved and have value added to the card for future use? It is just a one time use card stock? Just want to check for discarding them.