May I ask what kind of subscription(s) have you had?
Was it plan type or some other e.g. Argo, etc.? 
Helpful article to check and to understand if you’re on the period of the renew of your current plan type or not?:
Furthermore, in such scenario, may I ask did you followed the instructions to cancel your subscription and disabled your service as stated on the article below?
The alternative is to cancel the current plan and subscribe again with the correct billing cycle. Cancellations are only processed by the end of the billing period, so your plan will not be downgraded.
Regarding the refund in general for plans here is the cite:
4.3 No Refunds
FEES ARE NONREFUNDABLE. YOU WILL BE BILLED IN FULL FOR THE SUBSCRIPTION TERM IN WHICH YOU CANCEL AND NO REFUNDS WILL BE PROVIDED FOR THE UNUSED PORTION OF SUCH SUBSCRIPTION TERM. Following any cancellation, however, you will continue to have access to the Paid Services through the end of your current Subscription Term (except with respect to Services subject to usage-based billing). We may, in our sole discretion, provide a refund, discount, or credit (“Credits”) to you in a specific instance, however the provision of Credits in a specific instance does not entitle you to Credits in the future for similar instances or obligate us to provide additional Credits.
Source article:
If it’s related to the domain renewal process, if so, should have disabled auto-renew option:
Registrar transaction fees for domain registrations, transfers and renewals are non-refundable.
3. FEES
3.1 Fees. You shall pay Cloudflare the applicable fees for the Registrar Services (“Registrar Fees”) prior to the registration or renewal of a domain. All payment obligations are non-cancellable and non-revocable, and all amounts paid are non-refundable. You agree to pay any and all prices and fees due for Registrar Services purchased or obtained from Cloudflare at the time you order the Registrar Services, unless set forth otherwise in your Enterprise Subscription Agreement Order Form or Insertion Order. You acknowledge and agree that you may be charged Value Added Tax, Goods and Services Tax, or other localized fees and/or taxes, based on your bank and/or billing address.
Source:
Thank you for writing. I am sorry to hear this happen.
I flagged your ticket for the team in the Support, since the Community cannot see account details and provide further help. Support will respond to you on that ticket.
Please, no more tickets are necessary to create, since it just slows replies to the time of last ticket.
Questions about billing will need to be resolved by the Customer Support team and cannot be resolved on the Community. You’ll need to follow these directions here: