A few improvements/fixes on established website based on Joomla/PHP

I run a commercial website based on Joomla and a third-party Joomla plugin, which is rather extensive. It's a niche plugin, a full software actually, not popular and not good documented, so you as the programmer need some in-depth PHP knowledge. Here's what I need done: - The recurring credit card payment processor is [login to view URL] (2co) and they recently changed their API calls or values that they send to our site whenever a recurring billing gets triggered. Since that change, payments no longer arrive properly into the database and we need to add them manually as a work-around - Payments from users need to get approved manually. There's already a database field where you can choose between "New user" and "Approved user" but it doesn't do anything at this point. I need this to get extended so that when I switch a new user to "Approved" that all payments that arrive from this user will get approved automatically, and there's no longer the need to approve manually. - A service that the customer purchases runs for 1 month usually. When that service expires, in certain circumstances (e.g. recurring payment set up, but no payment was arrived = meaning usually that the credit card has expired or it didn't have a positive balance) I need an E-Mail to get sent to that customer as a reminder to add a payment manually instead. Probably a few more minor improvements... Joomla is version 1.5.23 CentOS 6.10 PHP 5.3.3 MySQL 5.1.73 I will provide SSH root access. NDA is required. We will communicate via Skype (chat). Thank you!