Just a dollar

I had the oil changed in the car the other day and a question has yet to be answered. I have been pondering this for years now and would really like someone to answer it for me:

When I take the car in to have the oil changed, there is ALWAYS a charge for filling up the windshield wiper fluid. It’s not expensive, but nothing else gets filled up. Why is my windshield wiper fluid always topped up without asking me? They can’t call that a “courtesy” because they CHARGE me for it. You don’t go to a burger joint, have them give you fries because they thought you looked really hungry and then charge you for them. Half the time I swear it doesn’t even need to be topped up but there is always that $1. charge

Yes, I do realize it’s only a dollar but it really pisses me off. Is it just me?