Hi there, Ed.
To assist you better, may I ask what role you have in your QuickBooks Online (QBO) account? Your role might be why you can't see your customer in the lists.
Please ensure you're logged in with a Primary Admin role to access all customers' lists.
If you're the Primary Admin but still can't see your customers, try refreshing the page, logging out and back in, and then checking the customer lists.
About your online billing system, are you using Bill Pay? If so, please note that QuickBooks Bill Pay requires a subscription. The issue might be that your free trial period has already ended. You'll need to renew it to continue using it.
The email is likely about PCI DSS Compliance Services for secure payment processing. Since you’ve paid $80, please check your email for further instructions.
Let us know if you need anything else by leaving a comment below.