Bad customer service

I got a cal from this number ***. The agent said she's from Vodacom, it seemed as if she was gonna help me with my query.She asked whether I wanna cancel the contract . She said she'll get back to me after speaking to her manager she never did. I took a contract in September at a Vodacom Express Shop. I tried everything even calling customer care and after sales , even going back to the shop didn't help. Customer care refused to lodge a contractual dispute. Says the store cannot be held accountable , it's my fault. I got a call from an agent who said my query is " vague" . I will never trust Vodacom again. I'm very unhappy. How can this be escalated any further?