Travelstart misleading advertising

Capitec advertise if one books a airline ticket through Travelstart, you will get R100.00 off your flight ticket if paid with a Capitec card. So I booked on the Travelstart website but did not realize there is a special link where to book to get the R100 off. I was charged an additional R180 for my booking and no discount given. I referred the case to Travelstart ref [#861694] who responded I used the incorrect link and I will not be getting the R100 x 2 tickets or the R180 back. I feel this is unfair as I booked through Travelstart and paid with my Capitec card. Who in their right mind will book through a travel agency at additional costs if one can book directly through the airline?