Vodacom online billing adding device insurance

Upon scrutinizing my bill, I noticed that the device insurance was duplicated for one of my phones. Very cleverly the duplicate was named something else. I proceeded to the Vodacom shop in Centurion were the lady assisted. The insurance was phoned and the person on that side insisted that I did an upgrade in July thus the insurance instruction from Billing/upgrade. This is not the case. There was no upgrade. But the fact remains that I have been paying for two insurances which I believe is against the law. The one insurance is Comp Cell Insurance (R15 ********** 0) and the other Iphone Cover Band (15000). I want to know: Who gave this instruction without my consent? How is it possible that Vodacom fail to pick this duplication up? I am due for an upgrade, but I am seriously considering not doing so.