My usage for cellular data for apps is disabled!

Am having an iPhone 4s (version ios7) and when I turn off the cellular data for specific app and then when I close my settings and then get back to settings that app uses cellular data automatically. I didn't switch on the use cellular data for that app but it becomes green when I close and open settings>cellular>use cellular data for. Help me with this! How to switch off the cellular data usage for an app without letting that switch on again after closing settings and opening it again.