I'm going to ruffle some feathers here, but I can see where Cheshire Oaks are coming from with this.
They could easily retail that car in the showroom and expect a walk in within a couple of weeks, I've been there and worked in an Audi dealer and the sales managers have targets to hit, with margins too. Your name was against that car and they had you down as healthy profit. If they give you a nice discount now then the salesman loses out, as does the sales manager. Unfortunately that's how most of them think, short term gains. Also the sales department and service couldn't care less about each other, so if you're not going to service your vehicle with Cheshire, then the sales guys couldn't give a damn (sad but true).
HOWEVER, you've now gone elsewhere, they've lost your business and now everyone on here knows how unhappy you are with that dealership. Bad reputations are hard to shake off, look at Bexley, I've never been but I wouldn't ever go based on the feedback on this forum.
Glad you've got out of the car however and wish you well hunting a cracking deal for a new build.