HELP locking wheel nuts seized

[Mk2_pete]

Can't remove wheels from my passat as the locking nut is seized solid I've snapped my key and 2 that I bought from the local dealers I'm totally stuck as I need the off to fit my coilovers I can't even use a socket over the top as the have a rotating sleeve any ideas guys I need them off ASAP I've had a search and found nothing