I Was Charged Membership Fee Despite Assurance

Despite being verbally assured that I would not be charged a membership fee, a membership fee of ₺1149.50 was charged to my Akbank credit card two days ago. The last four digits of my card are 4574. I contacted customer service regarding this situation, but they offered no solution, and my requests for a refund or to close my card were rejected. Although I was verbally assured that I would not be charged a membership fee, I refuse to accept the charge and the lack of customer service support. I demand a refund of the membership fee.