I had this issue several times and ultimately managed to resolve it. They indicated they would weld a nut on within one minute, but it was only after that they successfully liberated it.I damaged my BMW key nut, purchased a replacement for £22, and nearly compromised that one as well. The garage ultimately removed it using an air gun after 30 minutes. I have now removed all locking bolts from my car and will replace them with four standard bolts, ensuring that whoever re-tightens them applies the correct torque of 120/125 Nm. My M4 currently has spacers, so I have extended locking bolts, but I plan to replace them with four extended bolts to match.