NOT interested in providing Customer Care

My son has had his MTN pay as you go number for many years. He has been abroad and up until a short while ago was getting messages which just stopped. Today a friend messaged him to say there was another picture on his profile. Called MTN Customer Care and from the "options" found that if a number is not used within a period of 90 days i make a call it is deactivated. Surely they could send a message before just deactivating and giving your number to someone else. They are quick enough to try and always sell you stuff but could not be bothered to contact you about your number about to expire or be deactivated.