I cancelled and was still charged the monthly fee
Customers sometimes report that they cancelled their subscription for our Barn2 Bundles & Bulk Discounts app, but a further payment was taken after the cancellation.
We understand how frustrating this happens. The reason is that your monthly app payments are combined with your monthly subscription for Shopify itself, and the timings are controlled by Shopify. Apps have a 30-day billing cycle and if you signed up on a different day of the month from when you signed up for Shopify, then the timings may differ. For example, usage charges from one app cycle might be split across two different Shopify bills.
Learn more about how Shopify times the payments for apps.
If searching the knowledge base hasn't answered your question, please contact support.