Dollarama review: Wrong price

On April 25, 2021, I got 4 plastic containers at $2.50 each The cashier scanned the items at $3 each. There's still lots of containers on the shelf its price for each it is $2.50.
The next morning I phone the store the lady said they cannot adjust the price. That was so rude.
I am so upset.
That's it you cannot do something about it. That's ridiculous.
You guys are disappointing. I have the receipts and the items.