Misleading advertising by Webafrica

I recently signed up with Webafrica which includes FREE installation. Vumatel arrived today and informed me that I will be liable for costs exceeding 30m of cabling. Firstly: VUMATEL installed the box on one end of the building with includes 2 businesses, main house & 2 Granny Flats. Why was this not installed at a central point of the ERF? Secondly: Webafrica advertises FREE installation, no mention of any costs exceeding 30m. Why am I liable for costs which is of no fault of mine? Why am I liable for any costs for the neglecence and misleading advertising of both Vumatel & Webafrica?