Contract upgraded but no data received

I have been trying to resolve an issue with my contract for close to a month now. I upgraded my contract in February 2016 and it was meant to come into affect at the beginning of April 2016. I have not received data for this month and I am unable to load airtime or data on my phone even though I upgraded to a top up contract. <br> I have made numerous calls over the past few weeks with people telling me they have elevated it and someone will call me back, but no one has. Over the past weekend I visited Vodaworld, customer service, they could not understand why they have not sent me my data even though the new contract it reflecting on the system. I requested to cancel my contract and they put in a service request and said that someone will call me back. No one has called me back. I just tried calling cancellations and they put me on hold as they say I am on some new system and they do not have access. I would like to cancel my contract asap due to the poor service from Vodacom.