incorrect credit card statement

May you kindly assist I have a query, I took credit card a and I was advised that I would pay 5% of the amount I used plus initiation fee and bank charges. My balance is R16641.02 and 5% of that its R832, bank charges amount to R389.72. so when I add them together they amount to R1221.72 which Is the instalment. To my surprise the statement I just received it say the minimum instalment I must pay its R3666.45, please explain to me how did it get there. i called credit department on friday but the agent was also confused she couldint assist, can i please have the correct statement.