MTN taking insurance money for something that is not insured .

On 17 Aug I claimed for a screen repair on my phone . On the 24 August MTN insurance declined it telephonic and said they will send me an email . On the 4 Sept I send an email asked for my declined email . On the 6 Sept I email again after I haven't received anything . After my second request they send me the email . I also asked on the 24 August that they immediately cancel my insurance and the lady on the phone said she already did that while we were speaking . I also said that I want my premiums back because the reason they declined was because the sim was not in the "covered" device from end of January. I told them that i did use the phone in the WiFi zone at my house . They said that its not covered if the sim card is not in the device . I' m fine with them not fixing my screen for that reason but then I want the premiums back that they deducted . They said no and also that they will only stop the insurance after 30 days notice . My question to them is why they took and still take my money if there is nothing to insure ? The device is damaged so the sim card is not in it so then its not insured , so for what did I paid and still paying . They said is stated like that in my contract , that I must give 30 days notice.I then asked for the signed contract . The next day they emailed and said they can't find the signed contract . Today at the MTN shop when I asked them if the insurance is canceled they said no its still reflecting on my account . Why ???? And I still wait for my signed contract otherwise I want my deducted premiums back from Feb 2018 .