How to stop autorenew for calls & SMS (no expiry date) on Safaricom

I wrote a post about Safaricom calls & SMS airtime with no expiry date – a service introduced in 2019. In the post I showed readers how to buy airtime via the *544*2*Amount# USSD shortcode. One thing you will realize is that once you purchase airtime this way for your line / another phone number, you