Tira here, from Shopify Support.
Is there a reason why you cancelled your store? If there's anything I can help with that you are struggling with, please let me know. I would be happy to provide you with guidance and resources to help! If you have any feedback for us as well, I would love to hear what that is so that I can pass it onto the right team so that they are aware of how we can improve.
We typically do not offer refunds as it is against our Terms of Service. I would be happy to take a look at your account to see if we can make an exception in this case, as you cancelled your account when the billing period started. I have sent you an email to the email address listed on your profile. If you would like me to take a look, please reply to my email and we can go from there!
I look forward to hearing from you.