What's an extra $9?

I had to go buy a battery for my vehicle today. I had someone help me find the right one and when I went to pay for it they wanted an extra $9 for the core charge. I asked them why they would need that when I was paying $95 for a new battery. They said I could bring my old battery in anytime and get refunded. So of course I started crying. He took care of crap like this. I haven't had to worry about car stuff in 13 years! I refused of course and went home with no battery and decided I will worry about it another day. When I can focus. Which might be never.