Paypal IPN System for Wordpress Site Set up

Need someone to add a subscription function to my website using paypal's Instant Payment Notification service. User must be billed every month according to the price (which I should be able to change the price when need be) User must receive random generated User name and password when they become a member and pay the initial fee. System must be automated to delete username and password when user fails to make automated payment. I have most of the system set up so dont expect me to be paying hundreds of dollars for a couple missing lines of codes. I have a plugin called "Paid Membership Pro" (research it) I would liike to use. I found it useful for adding new members but, automatically deleting them if they don't pay is my main issue. They also need to be able to cancel their paypal subscription if they cancel their account with my website. Please message me on your methods to let me know you understand what I need and read this description.