Settlement of a credit card that I didn't use

I would even rate it a zero. I recently opened a platinum credit card and was disappointed with the benefits, as they did not match what was explained over the phone. I filed a complaint, but it remains unresolved. Consequently, I decided to cancel the card without making any transactions. Now, I am surprised to find that I am required to pay a settlement fee of R546.64, despite not having spent anything on the card. I feel misled, as the information provided seemed incorrect, and I am now asked to pay this amount. I find the situation quite unfair.