Ughh ... that dreaded corporation attitude ... With the discount you probably need a printout or something to argue otherwise it will be wasted energy. Complaints will likely be handled by someone with a similar / defensive attitude and will leave you a bad taste. If it was a local bike shop, it you have made a difference because these people care about their customers, but again this probably wouldn't have happened in a LBS.
As for the scratch, it's pretty much the same. The salesman doesn't own the business and couldn't care less if he sold a bike or not as it will not affect his profits for the month or his reputation. I've been to
Evans in lakeside yesterday to look at bike and spent a good half a hour without a single person asking if they can be of any help. I had a few enquiries but I had to queue in order to address them so I left. Today I bought a bike from a local shop and pretty happy with the service and deals that I received.
If you need to feel better, you may consider the scratch and possibly the loss of the offer the price you paid for the opportunity of sampling and testing several bikes given the circumstances. If you feel you want to pursue this further, you can write them an email asking where and how to file a complaint. All companies like that are required to have a complaint protocol in place which should make available to you and if I'm not mistaking, they are require to contact you back after they looking into it. In practice however this hardly ever happens and you may be spoiling the joys of the new ride with a bad experience.