Incorrect contract and no way to fix it

Vodacom called me and offered me a 2GB data contract with a wifi-router. I was then offered another 4GB contract with a router. I accepted. when i got the activation sms both numbers were for a 2GB contract. i went into a vodacom store and they told me they cant help me because i didnt deal with them originally. I've tried calling customer care several times and the call just drops before i can speak to anyone.