Foschini Billing Nightmare

I have been with Foschini's for over 10 years. My account has always been up to date and never complained about my account. Recently I paid my account off and took a cellphone on the account which had cellphone insurance. There is a running balance that they brought over after the account was paid up which they could not explain and they have not cancelled my cellphone insurance since I put through a request at the beginning of the year. They have now sent my account to collections who are still sending me a total to pay INCLUDING the cellphone insurance. I have spent almost every day calling them to try and get these amounts reversed but not even the managers are willing to help. At wits end and cannot believe they are just taking money like that. Check your accounts.