Instacart not honoring their prices!

I ordered Instacart store pickup the other day and noticed that the price in the app was not the same as what I was charged. I pointed this out to them and they are refusing to refund me the $1.00 price difference. I get that $1 is not a huge deal; however, if they are allowed to do this to every customer that really adds up in the long run. I’m shocked that they are even refusing to credit me the $1 after submitting screenshots of the item in their app and what I was charged. Also, I think it’s kind of ridiculous that they can adjust the weight of meats to the point you’re paying almost double. I requested $9.98 worth of chicken and it was adjusted to almost $17. That’s a big difference