Sounds like more than a ‘small’ bump if it’s broken headlamp mounts, although maybe it’s a French car made out of tin foil? 😉
Anyway, as to your question, my immediate thought was to ascertain politely why they were unable to do the agreed work yesterday. It may be that there had been a family trauma, a close relative taken ill, dead, involved in an accident, or eaten by a crocodile, mauled by a bear kinda thing. So perhaps tread carefully before going in all guns blazing.
OTOH, they may have been partying really hard since last Thursday night, in which case and as we all know, the best weekends like that don’t finish until Tuesday, or until all the drugs run out ( in which case, if that’s before Tuesday someone will know someone else and more drugs n booze will be acquired to take everyone through to Tuesday). In which case, don’t bother to call them until tomorrow and go easy cos they’ll be on the come down and likely to ask you to take your damaged car somewhere else.
Alternatively, they forgot all about you and decided to make the most of an impromptu sunny weekend.
HTH