Requesting a refund for an accidentally purchased annual Google Space subscription

i recently purchased 30 gb extra google space annually by mistake,i had intended to do monthly asking for a refund has been daunting seeing as its not showing up on my subcriptions and iam yet to get a refund on my card.I had hoped when i picked what i needed it would appear as an error than anything (i was just being hopeful or positive )

[Re-Titled by Moderator]

Original Title: refund for wrong purchase