Terrible online shop

I ordered 2 windows online for my bedroom that we are building. It showed in stock, and fulfilled by Leroy not by a third party seller. I then received a phone call later that day that they will only have stock in 4 weeks time. Then why was it listed as in stock on the website!? I have now had to source windows elsewhere as we need them this week. I phoned again and the informed me that a refund will take 7-10 days. How is this even possible!? Ridiculous runaround for no reason.