Cheated by insurance company

Good Day .. For the past 4-5 years I’ve been paying insurance with Hollard for my sister’s cellphone.. 18 months ago her phone was damaged and replaced no hassles. Currently her new provided phone has issues which means it needs to be taken in for repairs .. Suddenly now they will not authorise the repairs and it’s non insurable something like that and claim was rejected .. My question is every month you been taking my insurance premiums but now you don’t not want to fix the phone and this is just because I gave the phone to my sister which immediately means it’s no longer mine .. she’s using the device .. I have my own device I’m not a merchant or a drug dealer to need two phones ..

Am I being unrealistic to expect all my premiums that I’ve paid back since they not willing to authorise claim?

Any advise?