i know that it seems there's not much interest on this thread (which i'm glad about as it must mean no one else has this issue with their runflats) but i've got an update
finally (after 6, nearly 7 weeks) i have had the phone call to go into BMW and have 3 brand new runflats fitted to my mini!!
it took a stern email to get through to them that i wasn't going to leave it! i copied in my sales guy, the mini garage's manager, williams manager, mini customer services, haha basically everyone who's anyone...
and i got a call from the tyre guy yesterday enquiring.
so i'm not totally happy as i still had to pay for a new tyre, but it had a puncture anyway, so i will now end up with 4 brand new tyres, and one that isn't cracked as a spare!
just thought i would update this thread, as if anyone else has a similar issue, my advice is to email, and don't give in!!