I can't buy a game because I have already bought it in the PS Store on PS4, what can I do?

I wanted to buy minecraft in the PlayStation Store on the PS4 and had previously tested the demo version. Now I wanted to buy the full game and I can't because I supposedly bought the game but I didn't buy the game but only the one Demo version played if I click there to show more then it says that I have already bought the game but I have never spent money on the game Minecraft on the PS4, I can fully remember it, can someone please explain to me what I can do would be very great I'm really desperate

Then just download it again.

Sometimes you can still choose a specific version of the game so that only one option is not available.

Try buying the full version of in-game. Say, see if you can buy the full version in the demo.