Family Dollar review: pricing integrity

On 6/20/2019, I shopped at Family Dollar store #11795. I bought 4 items, one of the items I bought had a shelf price of 2.85. when checking out, the cashier rung it for 3.50. After getting the receipt from her I told her that the item was not 3.50 but 2.85. She then called the manager on duty up. The manager informed me that she could not give this item to me for the shelf price and that the only solution she could do was to refund the item. I then told her that I wanted the item, but not at 3.50 but at the price that was on the shelf. I ended up having to refund the item. I then told the manager that that decision was not fair because customers do not price their merchandise. It was also not my fault it did not ring up correctly. My desired solution would be to put competent managers in their stores that can make decisions that make sense. Pricing integrity is normally not the fault of a customer, especially if the price on the shelf is labeled one price and it rings up a higher price at the checkouts. Being a Store manager myself, I know there are times when ocassionally prices are changed by the customer, but this was not one of those incidents.