Sorry for late reply to this - just got back from France (need to go back there on a bike...)
I spoke to Appleyards today and they said my bike is fixed...! (I'll confirm on Monday when I collect it).
They said they rode my bike back to back with a demo Glee and said they could see the problem I was describing (about time as they told Suzuki they couldn't replicate it).
First thing they said was the throttle was way out. Asked if I'd being playing with it which I haven't, but the reply to me was them saying the throttle was that far out no mechanic would have adjusted it like that... I'm guessing I must have adjusted it in my sleep then?
Next, they said they stripped both bikes down and started swapping bits from one to the other such as TPS sensors etc but had no effect on the issue, then put new sparkplugs in which had no effect. They then put the demo's sparkplugs in and the issue was fixed! The manager said he bollocked the mechanic for fitting the wrong sparkplugs, but the mechanic said he didn't and showed the sparkplugs from the service match the one's listed in the service manual, but these are different to the one's the bike comes with and the parts list confirmed this. So the manager is not happy with Suzuki as he says he has 16 hrs labour in resolving this, but at least it's fixed.
I also asked about my missing bolts, he said they put new ones in but their mechanic says they were definitely there when the bike came back to me and they couldn't have just fallen out as they're behind a panel... I guess they're saying I've lost them
Anyway, my bike is ready for collection on Monday and it didn't cost me a new chain at around £200. I'm hopeful it is fixed this time and will let you know. Also the manager wants to chat to me about this when I go in so will see what he says.