Refused Boarding Pass

I booked a mango flight for my brother to fly from Jnb - Dbn 26 June 2015. When he arrived ( with flight confirmation print out) and ID, from his flight from Qatar, he was told he may not use the ticket, fully paid for, as he does not have the credit card used to make the booking. The ticket is in his name, he presented his ID and he is a south African citizen. The ticket was paid for by me, on the 08/06. How can they possibly justify refusing to issue a boarding pass and force him to purchase a new ticket when the one I booked for him was fully paid for 3weeks in advance???? He was forced to purchase a new ticket and thankfully made it onto the flight but I expect that I should be fully refunded for the unused ticket! This was completely unreasonable of the person at check-in and poor staff training from Mango. Please note I have emailed Mango twice since the incident with no response or feedback.