Builders Warehouse installation fiasco!

On Saturday 13th Feb I bought an external door and other necessities at Builders Warehouse Erasmus park. I also bought door installation services. The installation is done by another company called 4 Sure, who seem to subcontract to whomever they can find on the street. The delivery and installation was scheduled for Tuesday 16th Feb. I got a call from 4 Sure on Monday confirming delivery and installation. By mid-day on Tuesday no-one had arrived. After calling Builders Warehouse twice and being directed to a phone that went unanswered, I asked for the store manager. The store manager was all apologies, but was unable to find the local person responsible. I got a call back from builders that afternoon saying that they were unable to get hold of the people responsible for the installation. I then got a call much later from 4 Sure sayings that they apologise and that they would reschedule to 10:00 on Thursday. At 10:45 on Thursday I called Builders Warehouse to find out where the installers were. The installers finally arrived at 12:00. At 18:30 that evening I escorted them from my property. The door is still not closing properly, the door has been damaged in multiple places, the locking mechanism (also bought new and tested working), no longer works properly, and the door handles (also new) are missing *****s. I have been in contact with a representative of 4 Sure, also highly apologetic, who has assured me that the door will be replaced, and professional services will be used for installation and that the installation cost will be refunded. Builders Warehouse needs to take responsibility for the subcontractors that they hire to do installations. I will be in contact with Builders Warehouse tomorrow morning and will amend this review depending on the outcome. So far, my advice, do not use Builders Warehouse in-store installation, find professionals!