How to request refund from a month old transaction

How can I request refund for a charge made in March? I canceled the subscription right away in March but was not able to request refund as the charge was not posted and I thought may be because it was free trail for 3 days but it got posted a week later and it was as Apple/bill charge and not as app’s name so I thought it was interest charged on purchases until recently I checked it was the same amount as apps. It’s a very big amount $106.99 I reached out to the app but they said only Apple can issue refund but us. It was a six month subscription but I canceled the subscription right away. When I try to request refund here on Apple support, it’s only showing my April charge. 😣 Please help!!