I don't assume many folks here, considering the channel, would have purchased a subscription of any kind from Google Play. But I only recently discovered that whilst refunding apps within a certain time frame that are one time purchases are quite easy; refunding subscriptions are not.
Even if you report within 30 minutes of the subscribing, they say it doesn't meet their policy. (It was for a Podcast syncing/podcast app for WearOS. Considering that it had no server side component, I wondered why it was subscription based.) I still kick that I paid for one year instead of going to Mobilism and requesting the folks to see if the app could be cracked.
FWIW, if you're in Europe, you have guaranteed rights to refund online purchases within a timeframe. I'm assuming they've factored that in, but worth knowing if not.