Despicable Service Recieved

We bought a Sequre Trellie Product. We were contacted regarding a date and time for the installer to come by, time was arranged, however the installer was almost 2 hours late. When the technicians installed the Trellie door, four parts of the wall was heavily damaged. The technicians did not say anything. We did not pay the outstanding balance yet, as the door was not made according to specifications arranged before hand. We were informed that Sequre Trellie could not adhere to the custom sizing / spacing as required...and we informed them that our wall was badly damaged if they can grant discount (as they have in the past, due to their mistakes). We were informed that they will not give discount as their technicians states; that they asked us to fix the wall while installing....by the way this never happened. We have done business with Sequre, prior to this specific incident and we have always experienced some sort of complication. From the technicians leaving the working area very untidy, to damage to our walls, from not installing correctly, to not having all the parts on the day of installation and not providing the guarantee documentation (to my guess, probably a method to avoid claims). We always managed to find mutual ground with problems...but our last experience will in fact be OUR LAST experience with Sequre Trellie...as they did not show any compassion or regard to the service they offered.