Unreasonable Charge for a unassembled box sealed bike

Pathetic Service, After today's experience will definitely avoid flying mango in the future and will make sure my family also don't fly mango. Mango just wants to milk their customers for money, I was made to forcefully pay for a unassembled bike sealed in a box. Flying from Joburg to Durban with SAA and the bike was taken as part of check in luggage and did not have to pay a cent but when it comes to flying Mango this suddenly is not part of check in luggage although it's unassembled and sealed in a box, you're made to pay 385 or leave your box and fly. Booking with mango was a mistake I made after long time and will definitely not make it in the future.