How do I get refunded

I really need help. I wanted to take the free trial on the app Langotalk when I went to head to confirm the free trial by double clicking and showed €89 and by the time I realised it had already face ID me and charged my account I requested a refund for scamming my request was F declined and it said unavailable for refund !???! I really need help. I’m just 18-years old trying to save money in buy food for myself I really need this money