Unapproved purchases from a minor

My child purchased AED2000 work of Fifa & Robux games without my approval. I have used the 'report a problem' module on the app I have managed to receive one refund but have used all the chat boxes therefore I can't justify this any further. Im struggling to reach an agent too.

Im looking for a number who I can call and hope provide me with a refund, given my purchase history is for Extra space and not gaming apps.

Thank you

An upset Mum!