Roblox and Google Playstore worst security ever!

I have many accounts with my credit card linked, but the company with the worst possible security system must be Google Playstore and second in command Roblox. I have done everything I can, but still, my daughter gets to purchase extras in the store without her even realizing it—amounts of R399 - R999 and more. As soon as I realized I would contact them and NEVER do they refund. I have purchased online deals before accidentally and then the company would at least refund partially if not the whole amount. The result is me unsubscribing from every possible app on Google Play and removing my card. I know many banks recommend virtual cards which I must still explore. But it is sad as there are many great products on the Google Play store such as books etc. I would expect better service from a big company as Google.