Cancellation of insurance

I would like to lay a complaint against sterns, i keep on getting letters and phone calls regarding my account that is in arrears when i owe them nothing, when i finished my account i went instore, at sterns promenade and Tarryn assisted me with cancelling my insurance on my account. its been 6 months already and everytime i get phone calls to work informing my account is in arrears, i am tired of this can you please get someone to contact me that will actually be cancelling my insurance, as i wont be liable for any arrears. I got a call saying they will hand me over to the lawyers.<br> Thank you <br> Claudia Hartzenburg