TERRIBLE Manager decisions

I went into their store yesterday to buy a Smart TV. They wanted me to have a TV license, which I do not support because I do not watch TV - I haven't watched anything remotely like normal TV in more than a decade now. But fine, the TV has a tuner, and their employee (who deserves a positive review on her own), points out that there is a Dixon Panel secondhand, and it doesn't have a tuner so doesn't need a TV License. I say great, we try it out, it's perfect. I try to pay. The person behind the counter says that their manager says that the item needs a TV License even though it is just a panel (monitor), because THEY incorrectly logged the item as a TV (it was secondhand). Any reasonable person then says okay, so correct your mistake and let me buy the item? Nope, not them. They direct me to the new panels instead. I am not sure if the manager was trying to keep that panel for someone they know or not, but their decision yesterday cost them a decent sale of everything I was going to take. How is it that someone is in a managerial position there and doesn't have the brain capacity to address the real issue, which is that they logged the item incorrectly and that should be fixed? I'm usually a frequent buyer there, now they won't see me again.