Yes, I complained by email to ride2work at Evans, customer services at Evans and copied by my email to Scott Sports (the bike is a Scott), Madison UK (the brakes are Shimano)and my firm's HR team.
The bike was clearly ex demo. The Manager (who has now been moved from Holborn to Waterloo) was surprised when I didn't want to pay the full price. I said if the bike had just come out of a box I would pay full price, otherwise I wanted a discount.
My emails produced a discount of 10% on the bike. A further flurry of emails about subsequent appalling service produced a £50 voucher.
The brake pads still rattle, but I haven't taken it back yet as I am off t'bike for the moment because of my knee operation.
I don't expect all shop staff to be uber-knowledgeable BUT they should just politely say "Sorry madam, I will find out/find someone who knows" not f*cking well patronise me!!
Oh yes, I also complained about the website suggesting they have the goods in stock when actually they do not have the goods in stock. I said it was "Disingenuous at best and downright dishonest at worst" - one of my very favourite phrases.