Mango Airlines - *******

I did an on-line booking and purchased flights on their Happy Mango sale. My computer setting auto-corrected one of my children's name. I confirmed my payment and when i received the invoice, i had noticed the child's name was incorrect. I immediately went on-line in an attempt to correct the name, and noticed that they were going to bill me for correcting her name. I called the call centre and explained my error, only to be told that there is a cost applicable and i need to correct it on-line. I explained that i literally just booked the ticked not even a minute ago, and asked if they can not just correct it. After 15 minutes of trying to get my point across, i was billed R420.00. I told the manager that the amount is a price of a one way ticket price. I also suggested that they have a window period allowing passengers to make corrections. I was billed for an admin error which i corrected myself, with no staff of Mango actioning this.The ticket was not issued, as the flight is for later in the month.So i am confused as to the reason for the fee of R420.00. If anything i made Mango and Telkom richer, as i waited for over 15 minutes for my call to be answered. Day light *******.