Bad service MTN

Good day I would like to complain about MTN giving us messages on a contract phone but they are not going when sending to other phones. I tried to call customer care last week but there was no assistance however the matter was escalated but I have not receive feedback. I even went to MTN in Alberton in the morning on 07 April 2021 but the lady who was on duty was not friendly at all. She told me that they are franchise and they cannot assist me. I am amazed as I bought the phone at MTN in Alberton. This is not happening for the first time and the messages are expiring on the 15 of every months. The reference number is ***. Kind Regards Dawn ***)