Here's a long shot that worked for me once. My situation had round nuts with an internal adaptor for a lock. I used a 12 point socket that started to fit over the nut, but wouldn't go all the way. Pounded that thing on hard, which engaged the nut enough to cause enough friction to get it off. This was on a truck with drum brakes. Doing this on my Volvo I'd worry about warping the rotors, but if desperate enough and willing to pay for further damages........

How about some other ideas members?

Jester
2001 V70 T5, and a now gone 1973 P1800ES (370K).