kulula bluff and no fine print

I want to get more clarity on the options for the following but it is just impossible. This coming weekend is one of the biggest events in Cape Town south africa. Kulula requests from you to pay an aditional R700 for your bicycle to take it to cape town from johannesburg. They do not advertise it no where. They do not give you extra info on it NOTHING. Does this now give you a extra amount of kilograms to take down your bicycle? Are you still only allowed to take 20kg only? My opinion is then why do I pay the ekstra r700 if I dont get ekstra kilos? then I pay that amount and overweight?