Telkom (**********), adding items to customers bills, without their consent

Hi This month a looked at my statement from Telkom and I notice there was an additional item on my bill for R120,with a description device subscription Fee.I did not request nor did I give consent for a new device. Telkom are adding extra items to their customers bills, which is considered *****, and if Telkom does not remove this cost from my bill I am going to open up a legal case against them.