MTN's customer service sucks!

MTN has a glitch with their billing system but decides to threaten loyal customers with disconnection. I have received 4 threatening SMSs due to MTN's system inefficiencies. February has 28 days for 3 years and 29 in the 4th year. Did MTN only realize now that their system can't handle the shorter month? If MTN disconnects my service, then I am cancelling my contracts with them. I will talk with my feet if MTN thinks they don't need my business. I have been a loyal customer for over 20 years and this is how I am treated.