Why is a company like this still in business!!!

What a nightmare! False promises on delivery date. When eventually delivered, discovered the item was faulty. Then we have wait for their installation guy to eventually come around to confirm the fault... Installation guy eventually comes around to confirm the item is faulty. Then we have to wait for the incorrect part to be collected... again, many days later. They eventually collect the faulty part... over a month later of constant back and forth amd several visits to the shop and things are still not right. Never again!