I had asked for $20 dollars cash back. I tasked if...

I had asked for $20 dollars cash back. I tasked if I could have 2 $10's. Which she didn't have so she gave me 1 $10 & 2 $5's. She gave me the moneyb& receipt with the amount circled & her initial circled.
I went to text my son thatbi was on my way out of the store & saw WHERE he wanted me to get some chew for him.
I asked the cashier WHERE I would need to get it from & she told me line 9. So I left to go to line 9.
When I got home I realized I didn't get two items that I wanted. So my son called the store.
I just wonder since she knew where I was going why couldn't she have had someone bring the bag to me at the line WHERE I was waiting to get the chew instead of having to have my son drive me back tok your store.