Refund denied for accidental and un-used purchase

My refund request for a poorly made app’s subscription was denied twice despite the fact that ive never used it, I wasn’t the one who bought it and it was purchased accidentally. Aside from that, the app is of poor quality and the premium features i have recently checked don’t even work. No one is replying to me and i have nowhere to go. I may have to dispute the charge with my bank but i need to make sure that’s legally okay first and it might already be to late.