Changes to php/msql notification email

Currently we have a php/mysql database of subscribers to our webservice. As part of our customer retention strategy we send a reminder email using a cron job (I think) that sends a reminder email to active customers when they haven't logged in to our system for 3 months. However there are some months when we don't want this to run. That is in the months (Dec,Jan,Feb,March,April). We engaged a developer from freelancer to make this change for us but the notification still went out to people over the last few months. The job runs every Monday morning I think and we need to make sure it is working and find out what has been wrong with the logic and why reminders are still being sent. My guess is that it is just some basic error in the logic with the code but need to get this fixed before monday. Would estimate that this is only 1-2 hours of work. However what we are really looking for is a reliable mysql/php developer with access to graphic designers that we can use for all our web support. And would like a quick response time when we log issues. So even thought this is a small job we will end up doing a lot of other small jobs over time if we can source a reliable partner.