Very bad experiences with this merchant

I've had quite unpleasant experiences buying online from TechHut. The first time, I bought Solar PV Mounting Rails online and made the payment. I was in such a hurry that I wanted to send the courier to pick the order up instead of the free delivery because I wanted to do the installation that weekend. I then got a call saying that TechHut does not sell pv rails individually but as a kit. Mind you, I bought the rails from their website and they processed and accepted my payment for the rails, not a kit. The refund process took a while and I dismissed it as one of those things that happen maybe once in a while. Three weeks ago, I bought 2x Longi 550W solar panels, which I resorted to while I actually wanted the Longi 555W panels. TechHut was going to deliver the panels as per the order but, later in that week, I got a call saying that they don't deliver solar panels. Again, no such message was displayed when I completed the order, not even on the order confirmation email. I unfortunately had to organise my own transport. After much protest, we agreed that I'd send transport on a Friday, which turned into the next Monday. On Monday, I was the told that they couldn't get stock, which left me confused because stock was confirmed when I ordered. By the end of that week I had to cancel the order as they could not fulfill it and I requested a refund on Friday 16 January 2026. All I've been getting is promises for my refund and as of today, 26 January 2026, my refund is still not received. Mind you, this isn't my money but my customer's. These excuses don't fly with customers and TechHut couldn't be bothered by the effects of this to my reputation and that of my business. This is not right.