Poor Service recieved

Sean Viljoen from We buy cars JHB South give such poor services and empty promises. So my Fiance bought a 2012 Mercedes A180 from them, and it needed a Aerial and touch ups on the Bonnet, so Sean promised that he wil get it sorted, meaning fit a new aerial and Glaze the bonnet, so it never happend, and wasnt at work that stage when we collected the car, so the bonnet didnt need a Glaze but a respray, that cost us now R5000, so Sean, where can i send the invoice to?? Very very poor service from him...