We received a notice of acceptance (aka completion) on a job and we are still unpaid. We have 30 days to file a stop payment notice however, I'm unsure if we can do that as a preliminary notice was not filed. The notice references CA civil code section 9356
Beyond stop payment or lien rights, which you may or may not have right now depending on some facts that aren't in the question, you would have breach of contract rights against whatever person or entity that hired you. A construction lawyer can run through your options with you and help you come up with a good plan of action.