Insurance company taking premium for an article that I do not even have

I HAD A NOTE 9 CELLPHONE LAST YEAR. I upgraded and went to the Vodacom store to upgrade and requested the insurance on the Note 9 to be canceled as I sold it. I received a sms to say my insurance was canceled. I thought that this was for the note 9. I never really look at my statement. The insurance company has been deducting R282 each month for a cellphone that I haven't had for a year now. I spoke to the consultant, and he said that I should go back to the store. They are Vodacoms administrator. I have a sms. R3000 is a lot of money insuring something that I do not even have. They refuse to even look at a refund.