MTN- CANNOT MAKE CALLS ON AN UNLIMITED CALL PLAN

I have a mtn superflex plan. I'm paying R299 per month, the plan includes unlimited calls. For the past week, I am unable to make any calls from my mtn superflex plan. I called the call centre, hoping they could assist me with this problem, the agent stated that, she can't help me as they have not received any training for the superflex plans. She wanted me email ***, but that email address does not exist. I then sent an email to customer care. I received an automated response but till now, no agent has contacted me nor has anyone responded to my email. Is no one willing to assist me with this problem??? I'm paying for unlimited calls but unable to make a single call! Very disappointed