Vodacom sucks

Pity there is no zero rating. Been trying to cancel 20g vodafone mobile wifi modem which has been on a month to month basis since my contract expired 4-5 years ago. They will not cancel this device for which I am charged every month because according to them I have a contract. They cannot prove this as I have never agreed to an additional contract other than the month to month. Have phone several times and keep on getting the run around. The call center will not put you through to a team leader and the promises of looking into this matter, sorting it out and getting back to me is never fulfilled. It seems that the call center people cannot think independently. This is now tantamount to *****ing my money with the debit order that goes off every month for something that I want to cancelled and did not agree to a contract for!!!