Too much change

So today at Albertsons my total bill was 8 dollars and change, I give the lady a $20 bill and a quarter. She hands me the change, I grab my bags and walk out. When I get to the car I realize she gave me $17 change instead of $12. So I put my bags in the car and head back to give her back $5.00. When I walk up to the check out stand she looks up and in the most I could really care less voice says oh did I give you too much change. I say " yes here is your $5.00 back." She again without caring says thanks and goes back to work. Hey I am not saying I deserve a metal or a cookie but heck I just helped you have the correct cash at the end of the day. You won't be getting in trouble and I feel better for not stealing your money. I guess I was hoping for a bit more enthusiasm but oh well. At least I did what was right.