Contact trading standards in Audio Affair's locality for advice. This service is disgraceful and your experiences have completely put me off ever contemplating a purchase from them.
If you don't feel ready to go quite so far write a formal letter giving them a specified time limit in which to contact you, arrange delivery of the K2, and actually complete that delivery before you take the matter further. Keep a copy of your letter and send it by Special Delivery so that you have proof they have received it. If I were you I wouldn't be pulling any punches now. The excuses only wash for so long.
Hope you get this sorted. Its awful when you have spent so much money on new hi-fi to end up in this situation.
Excited about receiving all the bits and putting the system together...
I work for a Sony Centre. All opinions stated here are my own.