I don't know if it's a scam or not

Today, two strange things happened during my usual visits to the grocery store and Sayapark Mall, where I went to get dinner. I'm still not sure what to make of these situations, but they left me wondering if someone was trying to take advantage of me. Sometimes I feel that when you're a tourist, people might see you as an easy target.

The first thing happened at A101. I went there to buy two 5-liter bottles of water, which should have cost 52 TL in total. However, when I got to the cashier, she charged me around 72 TL instead. She looked a bit surprised, as if she'd just realized she'd made a mistake. I pointed out the difference and asked for a refund, but she told me it wasn't possible because I'd paid with my debit card. In the end, I had no choice but to take the water and pay the 72 TL.

The second situation happened later when I went to Sayapark Mall to get dinner from Arby's. According to the menu, my meal should have cost around 235 TL, but I was charged 245 TL. This time, I didn't say anything and just paid. However, I already have a little plan for tomorrow. I want to order exactly the same meal again, but from a different cashier, and see if the price is the same.