I understand you've canceled your Professional plan and are looking to get a refund.
Just to clarify how that works: we don't offer a prorated refund when you cancel your Professional plan. If you paid for that seat monthly, it will remain available for you to use until the end of the period you've already paid for.
Then, at the end of your current billing period, your team will automatically downgrade to a free Starter team.
Here are a couple of helpful articles you can refer to for more details: