In Pakistan at least, sometimes you can donate to charity etc by texting a special number [1]. That subtracts some fixed amount from your prepaid mobile balance (which the vast majority of people use) or adds to your postpaid bill. I imagine its possible for some business to charge customers this way as well.

Then again, instant C2C and C2B digital payments using mobile phones is growing extremely fast in most of the global south.

[1] https://www.app.com.pk/national/pta-introduces-9999-sms-code...