Oil sump nuts not tightened.. Shoddy service work

My daughter had her car serviced a week ago. She ended up stranded on the side of the road as they had not tightened the oil sump nuts after replacing the oil and the engine oil leaked on her way to where we live, 200km away, to nothing. This shoddy work potentially put my daughter, a university student, in harms way and potentially resulted in major damage to the engine.. We are taking this further as damage to the pistons is yet to be determined. The mechanic we used to help us resolve this emergency, was appalled at how these guys left the engine after a service as well as ignoring basic service requirements such as checking, cleaning or replacing air filters for example.