A few thoughts.
First, when you opened the store after the update the big red dot on your free bronzium should be enough. If you don't pay attention that's on you. It was nice of them to refund it but I personally don't think they should reward lack of paying attention.
2nd, great qol update. Having it easy to get to is great and even if I had accidentally bought a chromium, which I didn't, it would be worth 350 crystals to have this update.
3rd, it's 350 crystals. That is insignificant. If you accidentally spent that then you should just move on and be more careful. If you didn't and others are getting a free chromium for being careless, I know it's annoying they are rewarding carelessness but still insignificant so either way move on.