I can't find a cycling shoes to fit wide feet!

All
I've got wide feet and I can't find any shoes to fit. I tried on Shimano
and Diadora yesterday both too narrow and guy in the shop reckons it's going
to be a hard job to find shoes that fit. I've got 11.5/12.0 size feet and
it's a right pain when cycling as the base of the foot hurts and I have to
unclip from my time ATAC's and pedal using the middle of the foot.

Thanks

Gareth