Hitech safety Glass's pathetic customer service

The customer service at Hitech safety Glass is absolutely pathetic. I have a business that requires me to constantly be purchasing mirrors and glass for the goods I supply. I found that upon placing and paying for an order, nobody calls me back to follow up. Everytime I call in the sales agent is always busy and can't take my call. He never calls me back when I ask him to. Recently I tried calling him to find out about my delivery, he wasn't at his desk and so the other staff members there let the phone ring continuously instead of answering and notifying the client that the sales agent is not available. When I called back I spoke to a lady by the name of Ronell she didn't know how to handle me as a frustrated client and eventually cut the call on me. Delivery of the mirrors I purchased from them was supposed to be done yesterday, 16 March 2021, to my clients house. My client stayed home expecting Hitech to deliver and again they let me down by not delivering. They wasted my clients time as she cancelled all other plans to sit at home expecting Hitech to deliver. Not only did they not deliver but they also failed to call me and notify me that they aren't delivering. Is this how a professional company was supposed to treat their clients? I spoke to their sales manager and even after speaking to him nothing was done. Customer service still sucks