Client's personal account for viewing and paying for services?

Question

Payment systems

Given: Some set of self-written and motley software: web services, specialized software on localhosts of clients, 1Ski on a terminal server. Also non-soft services of the type: monthly service.
Task: There was an urgent need to be able to enable / disable all these services for debtor-clients. We need the maximum ready-made solution in the form of a client's personal account, which could be attached to the company's website, or at least on a third-party service that would allow:

1. See/disable/enable the client himself the list of services provided by the company.
   Roughly speaking: "You are now connected: 1. Rent of software "X", 2. Rent of access to cloud software "Y", monthly maintenance of your "Z". Total: NNNNN rub. Go to payment?"
   
2. Pay the client for services directly from the personal account. That is, in fact, integration with payment gateways. Namely: payment by non-cash account, non-cash from a card, well, completely perverted - "cash payment at the company's office."
   
3. An external API, periodically pulling which of the above software, we would understand that the service is not paid and you can pay off the account or access to some part of the functionality.
   
4. An admin panel through which an employee of the company could change the set of services, view minimal analytics.
   
5. Get standard accounting documents (PDF)
   
6. Notifications by mail/SMS about debts/debits/account replenishments
   

I realize that I’m asking for the impossible, but it’s lazy to write your own LC, what if there is a ready-made more or less customizable bike? Can you share a similar experience? Thank you.