Came out to call for a system not cooling properly. Customer stated that the system has to run at 69-70 degrees on the thermostat to keep it 78 degrees in the home. I checked system operation and found the pressures reading below recommended pressures, and temperature chart. I also noticed that my meter is reading 76-77 degrees in the home, but the thermostat is reading 70. Let customer know that he needs to have OG&E out to check thermostat and possibly replace it due to temperature difference. I also discussed doing a refrigerant charge on the unit, but also discussed leak search and replacement with customer. Customer chose to add refrigerant for now. If we have to come back for the same issue, customer will address leak search or replacement at that time.