Parental control did not prevent in-app purchases

Please can someone explain to me how it is possible that my 8 year old son was able to spend a stupid amount of money in multiple transactions in quick succession without the parental controls asking me for permission before payment went through?

I have all the controls in place. The game is Hungry Shark World and somehow he managed to purchase in-app packs for $149.99, $149.99, $164.98, $29.99 and $7.99.

My son thought it wasn’t real money.

I requested a refund from apple and much to my surprise I was refused. No reason was provided.

I appealed the decision and was rejected again, again with no reason.

I called apple support who told me the decision was final and I needed to lookup the terms and conditions. The support person was not able to give me any reason for the refund rejection and explained that the decision was final and I could do nothing about it.

I find this absolutely disgusting. I am a 25 year apple customer and including my business would have spent in excess of $200k with the company in that time. I am beyond disappointed in apple and how this has been handled.

Can anyone explain to me why an in-app purchase did not require my consent? And how apple can take this stance?