I just checked it and found the cause. Your ordered a service plan with max upload frequency of 1 image per 15 seconds. If you use a regular IP camera / DVR, then you will need to re-configure it to change the upload frequency. CameraFTP server cannot access/control your device.
If you use CameraFTP's Mobile Security Camera app, then it is different. The app can automatically check for service plan changes. If the upload frequency is too high for you, you can change your service plan online: order a new plan with lower upload frequency; then go to My Cameras page, click the Settings icon to edit the camera properties and then change the camera license; then go to My Account page, click Manage Subscription and cancel the old subscription.