How can a legitimate webApp subtract credit from a user's mobile phone for services rendered?

The title says it all. If a user gives their phone number in a webApp how can the webApp subtract credit from the user’s hone as payment for services rendered? I really need this for something I’m presently working on. Please reply as soon as you can. Thanks y’all.

This is what is called operator billing (WAP billing to be specific) and yes it does exist in other parts of the world, however, it’s still not being used widely in Nigeria yet. You’ll have to discuss with the operators about this. Ask them about WAP billing.

Thanks. How do I ask them? I’m in Ekiti doing my NYSC service. Should I go to Lagos and request for a meeting with MTN, Zain and Glo officials?