Bad bad service

I cancelled my cellphone insurance mid June 2020 and my insurance was cacelled with immediate effect but im still being charged up to this day, when i call them im being told that they sorry they fix it because the system shows it being cancelled and that they will refund me back my money, nothing has been done ive never received a refund infact im still paying for insurance. Each time i caĺl reporting the matter im being told it has been resolved.