COMRADES, Nigeria is suffering from acute poor power supply, but I don't know why MTN would be spamming customers with this useless message. Anytime the message beeps probably you're sleeping, the phone remains awake till the battery drains. And then person go begin the find where to charge phone again

Another worst part of this is that, when the unsolicited message popped in, the phone might be in your pocket and you might end up clicking the ok button unknowingly
Please, Nigerian Communication Commission kindly call MTN to order to stop this corrupt act

Change your phone notification settings to save your battery.

As for the annoying callertunes, Nigeria is what it is. The most annoying thing is that most of the tunes contradicts the customers' identities. You will call a priest and hear a tune that doesn't go well with the priest's identity.