Where can I buy softwear to unlock mobile phones?

Name and address of company selling it.

You'd have to look long and hard on the internet to find it, but it's not a recommended route to take...improperly handled, the software that unlocks the phone can damage other parts of the firmware on the phone, and in that instance the phone may not work, or work properly--and any warranty you would have on the phone likely would be voided by such damage.