https://support.google.com/googleplay/answer/2479637?hl=en&ref_topic=2450225

That is what I used

Hi if you dont mind can you tell me what you did to get the refund for TFL ? i tried visiting the google play website and i was told the refunds were available only 15 minutes into the purchase. Which email did u send the refund request to or how in the website should i navigate to ?

Thanks for your kind help