Did you not have this conversation with them when they told you the items were not covered under warranty? What did they say?
It is common for tyres, brakes, clutch and suspension items to be excluded from warranties. If they have experience with the claims department, they are saving themselves the hassle of claiming only to be told it isn't covered
Broken spring platforms are unusual, however, so I would hope that after some wrangling this will be covered. What car is it (S1/S2) and what suspension does it have fitted?
The flat spot issue might well be covered under warranty, but if they cannot reproduce it, I am not sure what you are expecting. Can you reproduce the flat spot issue at will? Did you demonstrate it to them? If so, then I would be disappointed they failed to reach a diagnosis, but otherwise I am not surprised ... put yourself in the mechanics shoes - customer complains of "flat spot" - you test drive it and it feels like every other elise - you're not going to get paid for any more work (you already resent the money you've spent so far, how would you like a bill for a whole day's work, only to report there was nothing wrong with it!!).
Yes, it's frustrating as a customer, but you need to work with them to get it sorted - bitching here is going to get you nowhere, I am afraid. Look on the bright side - the warranty is going to expire soon and then you can take the car anywhere you like
Cheers,
Robin