Bad customer service from Aerial Connect

I requested an installation of an aerial connection to another room, as well as rewiring of an existing wifi connection to another TV. I was grossly overcharged for unnecessary cabling and other materials. The work was done without providing me with a quote first. I was shocked to see the amount was in excess of R8000. I had no option but to pay it there and then as I live alone. and I felt intimidated. Their invoice states No refunds and a 3 month guarantee on the work. The next day I could not access the any of the Apps. I called them to come and check the installation. 6 days later and still there has been no one sent to fulfill their obligation.