Urgent help - Front brake problem?

[Baryonyx]

I have the below garage in mind for sorting the issue. They are well known local VAG specialists, and they looked after my brother's tuned SEAT Leon Cupra R 225 when he had it. They're not too far away.

http://www.swiftmotorengineering.co.uk/find.html

Someone on another forum recommended tapping the stuck brake assembly with a hammer. If I had a rubber hammer small enough to afford accuracy I may have been amenable to this idea. Any chance of it working? I can see the theory behind it, namely that it should dislodge the dirt stopping the calliper returning to it's usual position...