What MTN is doing is ******* 😡😡😡

I took 2 phones on contract from MTN in 2020 December however on the 16th of September 2022 both my phones would not except SIM cards and that went on for a week. Thought that it could have been as a result of updating iOS software but that wasn’t the case. I then went to istore so they could have it checked out and they told me that MTN has flagged or listed my phones as ****** hence they both not working. I then called MTN customer services and they were unable to assist as they could not see anything on their system , none of my details appeared on their system. They then advised me to go to an MTN shop so I could see a technician. I went there and spent hours and hours no one could help or find my information on their system. I got no help and I’m sitting with two useless iPhones 11 and 12 pro max. I’m frustrated.