New MTN SIM not working 2.5 months after it was delivered

On 8 August 2022 I received a new MTN SIM for a new cellphone contract. The SIM did not work - I got this error: "The SIM card cannot be detected or is from a service provider that isn’t supported. Try using an active MTN SIM card." On 29 August (21 days later) after repeated requests to MTN, the SIM came online and I was able to connect to Wi-Fi, but then I got a message: “Your service has been RICA barred. Please contact your service provider.” A constant flow of requests to MTN continued and it is now 7 weeks later - no one in MTN seems to know how to lift the RICA barring. This morning I was told that it is barred because my bill is not paid. This is complete ******* - my bill is fully paid and up to date and it is reflected as such on my MTN bill that I receive monthly. I don't know what I need to do to get this resolved. The people I have been dealing with are: Xolani Kubeka [ MTN SA - COSMO NET PTY LTD ] <***>; Tshweu Sekhampu [ MTN South Africa ] <***>; Lerato Mazibuko [ MTN SA - QUEST STAFFING SOLUTIONS (PTY) LTD ] <***>