I used OCUK for a long time, and whilst they were more expensive than other places I found at the time of using them that the service you got from them was excellent.
I then started to find that the service I was receiving was going down in standards after, they moved locations from the old office in a warehouse type building to a full on proper warehouse with office space, all to themselves as if they were getting to big for there own boots.
I had issues to the point I no longer can use them, but sometimes if I could use them I would because they do sell stuff occasionally that I cannot get from somewhere else, but that is on rare occasions as every company deserves a 2nd or 3rd chance.
When I did use them though, I always went to the store rather than ordering online because I hate waiting for a delivery van to turn up, and as I can drive and it's not to far for me I just went and picked everything up.
All I did was walk in with a list of what I wanted to buy, and generally if it was under £500 I wouldn't even think of asking for a discount, however if it was over then normally I would and to be honest most of the times I was given maybe £10 to £20 off something, or given something for free and it was nice of them to do that, as it felt to me that I actually mattered to them even though really I didn't, they just wanted me to keep shopping there.
Now sometimes I could spend upwards of £5000 in one go and generally that was when I had been asked, to build a few pc's by people and at that time even asking for a small discount would get me nothing but a look from the staff as if I was scum, and I just laughed it off and said there was no harm in trying.
I now only use Scan and I probably get a discount 99% of the times I go there, generally because I deal with the same person over and over again and because I am always polite, but I never have to ask for a discount the guy just gives me a discount if he can, and I don't expect it so I always if I receive a discount drop some money in any of the charity tubs if they have any, as a way of saying thank you.
When I worked for Comet nearly every customer wanting to buy a tv always asked for discount and generally they didn't get, one when they came to me because they were just flat out rude about it or they were just asking for to much, however if someone was polite and asked for a small discount then I would do my best to get them a discount, but sometimes my manager would say no and I use to feel really bad about it.
I got a mystery shopper come in the store one day, and the store was rammed full there was only 3 of us on the shop floor and because we were rushing to deal with, every customer mistakes were made and I remember being given a really poor review by the mystery shopper for not, giving a discount and it really annoyed me because someone expected me to give them something knowing that, what they bought was not only already knocked down in price but came with a free stand and dvd player.
I think to do what you have done here, because they didn't give you a discount is rather rude and obnoxious and just because you expected something does not mean that, because you didn't get it that, that company is poor or bad it just means that they obviously feel that they shouldn't have to give a discount code out.
Yes there is no harm in trying to get a discount, and I recommend people always try to get a discount if they can but what I don't like is when someone says that because, they didn't get what they wanted they are not going to use that company again.
Sorry if that seems harsh and rude but, to be honest if everyone who was purchasing items from somewhere had a attitude like yours, then there would be very good companies going bust all the time.