Ted here from Shopify, thanks for posting your query!
I'm sorry to hear that you didn't like the platform and would like to close the store. I'm happy to pass along any feedback you may have to better the platform.
It sounds as though you picked a plan within the 14 day free trial period but did not close the store before the first invoice was issued when the free trial ended. While I can not promise a refund without taking a look at everything in full, we can not review an account for a refund unless the store is closed. If the store is still active, I would recommend closing the store as mentioned in this guide. It's also possible to pause the account as mentioned in the same guide if you would prefer.
Before closing the account, you can duplicate your store's data to a device such as your desktop as mentioned here. This is handy to have on file just in case you need it again in the future and because some data may be lost after 30 days of closure.
Let me know how this goes and if there is anything else I can help you with, I'm happy to help!
Thanks for getting back to me! I've just popped an email your way to help authenticate the account and review everything in full. Please keep an eye out for my email and if there's anything else I can help you with, I'm happy to help!