How to contact Croydon/what to do?

I had a premium in-person appointment on the 23rd (i.e last Friday). I paid, gave my biometrics, but when it was time to consider my application, I was told they were having problems with some computer system and could not process my application on that day. So they took all my documents and promised to call me on Monday with the outcome of my application.

It's now almost a week later, and there has been no call (no missed calls, no voice-mails: the lady told me that even if I did not pick up the phone, they would leave me a voice-mail). I am understandably angry and fed up, as I need my documents and want to know whether I have been granted the visa, especially having paid for the premium service. The payment has come through my bank already, so no problems there, and I've checked to make sure the phone number I gave them was correct (it is).

More frustratingly, they gave me no contact details whatsoever, and when I call the main UKBA phone-line they tell me they have no idea what I am talking about and that I just have to wait.

Is there something I can do? Is there a way to contact Croydon directly, e-mail them, fax them?