Vodacom
Why can Cell phone Co's get away with STEALINTG?

I bought a new cell phone in December. Loaded Airtime and 1 GIG Data Bundles.
Asked the salesperson if I will lose my data if I do not use it and he said NO it will be carried over.
Now I received a sms notifying me hat the remaining 837.97 data bundle will expire tomorrow 28 Feb 2013.
This is like a deathblow to any State Pensioner. We have to try and live of R1200 per month and every sent gets turned around 4-5 times. How can the public be robbed of what is legally yours?? I bought it and it is legally mine, they do NOT have the right to from any person. If I buy a fridge or car or anything the supplier does not take it back from me because I did not use it in a specific time. Why can the Cell phone companies get away with and we must just sit back and accept it. This has to STOP. is a criminal offence. They need to sort this out, I want what is legally mine!