DM store on Šubićeva ul. 40 in Zagreb beeped me at the entrance yesterday

The alarm beeped at the DM store entrance yesterday. It's better to be beeped at the entrance as I can notice the store is fishy. It's worse when the shop only beeps the customer at the exiting time. Here, you see the entrance is unwelcoming me! I visited BIPA! next to the store for buying something instead. I'm making a database of such abusive stores. Any idea I can get a safe shopping store list for my own in Zagreb or other locations? As far as I know, Marine Pool in the Avenue Mall and HGSPOT at Spot tram stop kept one more kuna for some reason. Are they cheating on the customers by saying they don't have the correct change or just cheating the customers?