Staff know nothing about their products and are unhelpful

I bought running socks a month ago and did my first long run in them yesterday. I blistered on the side of my small toe. When I tried to see why, I saw that the socks had a little lump either side of the seam between the toe and the foot. This to my mind is clearly a design flaw and apart from alerting them to this problem so they can alert their supplier, I wanted - under the Consumer Protection Act - to exchange a faulty product (which I am entitled to do within 6 months of purchase). The manager who was called was clearly in no mood for this and first told me that I had to buy a seamless sock if I didn't want this. When we found the product on the shelf, it was clearly advertised as seamless on the packaging. Then he said look, all of the socks have the same thing. When I pointed out that this underscores that this is a design flaw, he said "you just have to turn the bump inside out" and then simply said he was not exchanging the product.

I made the mistake of buying my very first pair of running shoes from Sportsmans Warehouse about 20 years ago and endured months of blisters, essentially because the salesperson knew NOTHING about running or running shoes. I've never made that mistake again and now only buy from specialist running shops. Obviously nothing has improved in either staff training or attitude since. I bought these socks because I happened to be in the vicinity. Never again.