So Called Free Service Activation For New Contracts

I just upgraded my data contract. My phone is currently blocked and I cant make any outgoing calls, when I ask, I was told that I bought 50GB and I have reached my credit limit. I am currently on 2GB contract and one day I saw on the system that you can activate any once off Gigs of data for free, I then activated 50GB, which was said to be free. The next day i got an sms saying I have run out bundles and my phone will be blocked. When I call them, they say I have bought 50GB. I told them that it was said to be a once off free data for new contracts, but was told that it was never for free. I quickly went onto the system as I wanted to take the screenshot of the so called free service, but my account was blocked and couldn't go in. The 50GB that they said i have bought, i never got a chance to use it because my phone was blocked few hours after that. They say i must pay R2000 before my phone can be unblocked. I sent an email to log a query, but the ticket was closed as they say the issue has been resolved, but no one has ever came back to me and tell me what is happening. My phone is still blocked!!!