Sub Standard installation by Big Name Company

On the 26th of July I received a quote from Maxidor for the installation of their famous security gates. On the 28th of July I accepted the quote and transfered the full amount to their account! Fifteen working days later they sent an installer to my house to install the gates! I noticed that the installers were not working for Maxidor but were just sub-contracting for them! They got the measurements wrong and drilled unnecessary holes in the tiles! The plaster around the sliding door is cracked and can come off at any time! The rail is not fastened properly with some of the *****s missing! The doors are really not lined up and just a bad installation job overall! Phoned the company repeatedly with no response!!