Xenon Control Unit

[SO04UKC]

My driver side Xenon light is no longer on at all. I have taken it to Mini and they diagnosed that it is the Control unit inside headlamp that has failed and they have quoted me about £550 to repair. However i feel this is a 'little' steep! Does anybody have any idea where I can get the part i need or what the actual part no. is as they have failed to put this on the invoice/diagnostic report.
My car is a cooper S 04 reg.

Thanks for any suggestions :)

[SO04UKC]

I think i need a Hella Ballasts TYPE 3 OEM D2S D2R but cant find any other part website other than www.his4u.co.uk that stock it (unfortunatly these are out of stock). Any other ideas for sites please?