Negligence costing me thousands

On the 28th August I called in spoke to a consultant Noluthando Mthembu ..She assure me there's space still available for Intro to Samtrac Westville branch for 15 to 19 September (which is today) .. I confirmed on the call that in 5 minutes ill email her proof of payment and booking form ..which I did I have the emails as proof ..and phone records as well... Today my cousin is at the college and she is told she never booked for her they can't find her ID number on the system .. Whose fault is that? Shouldn't Nosa try to resolve thos since it's their staff's negligence not to do their job ? We paid R10 470 .00 for the course , R1000 for transport and R1800 for accomodation for her to be there specifically this week .. How should we going to recon these financial losses ?