MTN *****ing airtime

I’ve had a spare emergency phone with airtime in a positive balance for ages, and when l wanted to make a call recently l discovered that MTN had ****** my paid for airtime and recycled my number without my permission and without any warning ⚠️! I am disgusted that they are able to get away with this theft and would like to have it refunded and an explanation given. How many other people have been ********** in this way?