Correct Errors On Website

REQUIRED 1. Rectify code on file and in database (jem_invoice_payments) to ensure payment is recorded only once in the Sales records, along the sales invoices/payment path e.g. member invoices, print invoices, email invoices in admin backoffice, member invoices, emailed invoices, print invoices in member account. After making invoice payment, "status" and "Order Status" on "Manage invoices", "Print Invoice", "Emailed Invoice" is to read "Paid" and "Completed" respectively. Currently, "Status" and "Order Status" on "Manage Invoices" in Admin backoffice read "Paid" and "Pending" respectively. A particular transaction id which tallies with the online payment gateway transaction id amongst the 2 recorded transactions ids, as long as it will enable single-payment of invoices and ensure affiliate commission is generated, is to be retained while the other is expunged. 2. Code to ensure sales invoices are never re-used for another transaction DETAILS Currently, payment for products is being recorded twice in sales records and along the sales path and I suspect a particular code/sql query subsequently inserted sometime ago by a programmer on an online payment gateway file, as the cause. Suspect this code needs some modification. See the code attached When i remove a part of the code, sales transactions record correctly along the entire sales invoices/payment path i.e. single payment on invoices, database records single payment, "status" and "order status" can show "paid" and "completed" on invoice payment. In short, all this job requirement is met. Everything required is obviously interlinked, so solving the problem at root solves all requirements at the same time (see details below) The only drawback is that it impedes generation of affiliate commissions which is fundamental as this site runs an affiliate program. Apparently, one of the two transactions ids triggers generation of affiliate commissions. N.B. 1. Website runs on JROX Technologies CMS (core php) and is php 5.6 2. Skills required: Php Mysql 3. I will create 100% milestone at commencement but milestone payment to be released on completion of project, fully functional on my website. 4. Project to be completed no later than 3 days from commencement.