WORST BUSINESS experience I have had in my life!!

I would give no star but that is not an option. We have bought blinds through this company and when they installed the blinds we were not present. They drilled into into our doorway right on the edge and a 16cm x 8cm x 3 cm chunk fell off. The business proceeded to stick the broken pieces back with silicone which looked like a broken puzzle bulging out of it seams. I proceeded to talk to the owner about the problem where I was trying to explain that they cannot drill so close to the edge, He kept interrupting me and being rude while I was trying to explain what happend. Then the excuse was that my building was built badly and that it was a weak spot, laying the blame anywhere but their workmanship. As I was trying to talk to the owner, he proceeded to personally insult me and my family. He sent disgusting voice notes to my wife and I which is completely unacceptable and unprofessional. He sent disgusting voice messages up to 11 min long where he cursed at me and even proceded to talk about *** in a disgusting and crude manner (nothing to do with the topic at hand!). It absolutely horrifies me that this is the customer service I have received when their workmanship and business are clearly the problem. Never, in almost 20 years of doing business with numerous companies have I ever come across a business like this. I will do the repair cost on my own dime because the business owner is childish, immature and cannot listen to reason. I estimate the damages to be about R1000.00. If I had done the installation myself this would not have happened. It was certainly a rushed job at 16:00 on a Friday - you can be the judge. I wholeheartly recommend that you STAY AWAY from this business at all costs. Rather find yourself another business where your investment will be respected and treated with care. They will never see me again!!