Dstv Sends *****ulant Installer. No help

Dstv Tokai, quoted R3900 for decoder and R1500 for technician assistance to install and upgrade to Ultra package. The DSTV installer they sent charged me R9000 and intimidated me in my house to make immediate payment. DSTV Tokai refused to assist when I called saying they gave no control. I pleaded with Dstv Helpline and *****line, who is not assisting and telling me to phone the call centre, who us shocked but also offers no assistance. I have no idea what to do. I was ****** in my house by Dstv