Bad instalation services

If been waiting for my 10mbps line to be installed, for nearly 1 month The installer has been here up to 5 times claiming its the cables and that he'll fix it. I've been phoning non stop costing me over R200 in airtime just to find out they've placed two orders under my name, where I've only placed one ... not even receiving any progress on that one I've signed a 24month contract. They've placed my order again and yet again no service has been given. Fed up, wanting to cancel the contract to search for better service