We charge via Amazon Pay, so your email receipt will have come from them. Note that we charge subscription costs at the start of the billing cycle, and automation costs at the end. A list of payments to Prestozon will be listed if you log in to pay.amazon.com with the same email you use to log in to Prestozon.
You can also login to Prestozon to see your account(s) subscription status (dropdown at top right) and ad spend breakdown per marketplace, which will be relevant if you use automation.