Impossible to cancel with Vodacom

I immigrate to the UK and cancelled my contract with Vodacom in December 2017. After paying the early cancellation pentalty fee, Vodacom still charged me. I called to confirm cancellation again in March 2018, but still got billed in May 2018. I am now in the UK. There is no way to email Vodacom and I cannot call from here to sort this out. What does one have to do to cancel a contract with Vodacom. Really. I've cancelled twice. Can you please cancel my cotract and stop billing me!!! Please call me on the UK nr provided. I won't answer my SA nr as I am not in SA anymore. +44 instead of 0.