Vodacom refuse to contact me about canceling my service.

Trying to change my contract to a pay as you go seems impossible, support won't help me and keep redirecting me to *** which just doesn't answer my mails and seeing as I am no longer in South Africa do not have the ability to receive calls on that number. I emailed on the 4th and have had no reply at all. It seems the only way to get to them is to stop paying the bill. I have moved to the Netherlands so I am unable to go into a store, it's like they are holding me to ransom. I wonder if I can report this to someone other than vodacom as it seem ******* to force someone to pay for a service they have asked to cancel.