Walgreens review: Change from a purchase (coins)

3 times now I have gone to my Walgreens and after making a purchase they say they don't have any change. Then they offer to put your change on a card for spending next time you are in. This makes the 3 minute wait a 7 minute wait for 15 cents. I am watching several people say just keep it and several just putting their stuff down and leaving because it takes so long. I didn't mind the.15 cents but the other two times it was.77 cents. It appears that they are doing this on purpose.