MTN Insurance delaying my iPhone 12 claim and they keep asking for documents I have sent them

Good day my name is doreen Sitati, i have 2 phone contracts with MTN and they are both insured with them and one of my iphone 12 was once replaced by the insurance in Feb and they requested me to send the document received at store for the new device to be insured and which i gladly did so on the 10 February 2022, and now i have blacklisted the lost device and opened a police case and sent all the documents and now they keep on asking me to send the device box and i did so and i also sent them the replacement device document i received and almost every day someone new keeps on sending me emails asking me to sent the device documents and they telling me that the IMEI numbers do not match and i also sent them the documents after receiving the new device from them and they did not update it on their system, i did my part by sending them my device details and now i am in need of a device cause my insurance has always bin up to date, I lost my device on the 04 March 2023 and i reported the lost device within 24hours and opened a case and sent the claim documents to (***) and today its even more than 15 days with no hope of resolving my matter please assist