WHMCS Module for Softether VPN on CentOS

Hi, we have multiple dedicated servers with CentOS 6.7 installed and running Softether VPN with dedicated ips. I need a simple WHMCS module that will disable a user's vpn account when he doesn't pay on time and reactivate it when he does pay the invoice. That's all I need, I do not need it to issue vpn account automatically or anything like that, we will do that manually. We just need disable and reactivate feature thats it, thanks! Budget is $100